The Pseudoscorpion of Illinois

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BULLETIN of the ILLINOIS NATURAL HISTORY SURVEl HARLOW B. MILLS, Chief

C. CLAYTON HOFF

""''^^^m, ^/%

Printed by Authority of the STATE OF ILLINOIS ADLAI E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION

NOBLE J. PUFFER, Director

STATE OF ILLINOIS Adlai E. Stevenson", Governor DEPARTMENT OF REGISTRATION AND EDUCATION

Noble J. Puffer, Director

NATURAL HISTORY SURVEY DIVISION

Harlow B. Mills, Chief

\'oliime 24 BULLETIN Article 4

The Pseudoscorpions

of Illinois

C. CLAYTON HOFF

Printed by Authority of the State of Illinois

URBAN A, ILLINOIS

June 1949 STATE OF ILLINOIS Adlai E. Stevenson, Governor DEPARTMENT OF REGISTRATION AND EDUCATION

Noble J. Puffer, Director BOARD OF NATURAL RESOURCES AND CONSERVATION

Noble J. Piffer, Chairman A. E. Emerson, Ph.D., Biology George D. Stodrard, Ph.D., Litt.D., L.H.D., L. H. Tiffany, Ph.D., Forestry LL.D., President of the University oj Illinois L R. HowsoN, B.S.C.E., C.E., Walter H. Newhouse, Ph.D., Geology Engineering Roger Adams, Ph.D., D.Sc, Chemistry NATURAL HISTORY SURVEY DIVISION Urbana, Illinois Scientific and Technical Staff Harlow B. Mills, Ph.D., Chief Bessie B. Henderson, M.S., Assistant to the Chief

Section of Economic Entomology Section of Applied Botany and Plant Pa thology George C. Decker, Ph.D., Entomologist and Head Leo R. Tehon, Ph.D., Botanist and Head Cedric Carter, Ph.D., Plant Pathologist J. H. Bigger, M.S., Entomologist J. L. L. English, Ph.D., Entomologist J. L. FoRSBERG, M.S., Associate Plant Patholo gist C. J. Weinman, Ph.D., Entomologist S. C. Chandler, B.S., Associate Entomologist G. H. Boewe, M.S., Assistant Plant Pathologist Willis N. Bruce, M.A., Assistant Entomologist Robert A. Evers, M.S., Assistant Botanist John M. Wright, M.A., Assistant Entomologist Section of Game Research and Manage- H. B. Petty, M.A., Associate in Entomology Extension ment Ralph E Yeatter, Ph.D., Game Specialist Section of Faunistic Surveys and Insect Frank C. Bellrose, B.S., Associate Game Spe- Identification cialist Harold C. Hanson, M.S., Assistant Game Spe- H. H. Ross Ph.D., Systematic Entomologist cialist and Head James S. Jordan, M.F., Assistant Game Tech- Milton W. Sanderson, Ph.D., Associate Tax- nician onomist Lewis J. Stannard, Jr., M.S., Assistant Tax- Section of Publications and Public Rela- onomist tions Leonora K. Gloyd, M.S., Laboratory Assistant Tames S. .Avars, B.S., Technical Editor and Philip W. Smith, B.S., Laboratory Assistant Head Dorothy A. Moulton, Technical Assistant Blanche P. Young, B..A., Assistant Technical Section of Aquatic Biology Editor Charles L. Scott, B.S., Assistant Technical

George W. Bennett, Ph.D., Aquatic Biologist Photographer '. and Head William C. Starrett, Ph.D., Associate Aquat- Technical Library ic Biologist Marguerite Simmons, M..^., M.S., Technical D. F. Hansen, Ph.D., Assistant Aquatic Bi- Librarian ologist R. Weldon Larimore, M.S., Research Assist- Cooperative Wildlife Research ant {Illinois Department of Conservation and U.S.: Daniel Avery, Field Assistant Fish and JJ'ildlife Service, Cooperating) Paul Moore, B.S., Project Leader Forestry J. Section of George C. Arthur, B.S., Project Leader Willet N. Wandell, M.F., Forester and Head Lysle R. Pietsch, M.F., Project Leader Lawson B. Culver, B.S., Associate in Forestry John C. Calhoun, B.S., Assistant Project Extension Leader

Consultant in Herpetology: Hobart M. Smith, Ph.D., Assistant Professor of Zoology, University of Illinois.

This paper is a contribution from the Section of Faunistic Surveys and Insect Identification. (68424—2M— 11-48) ,^.^^^2 FOREWORD

During the latter part of 1946, all the vey of the pseudoscorpions. Dr. Hoff re- zoological collections of the Illinois Natural ported such unusual findings, and a fauna so History Survey were brought tojicther into much more extensive than had been ex- one section, formerly the Insect Survey Sec- pected, that we soon decided to make his tiiiii, which was then renamed the Section study the basis of a thoroughgoing faunistic of Faiinislic Surveys and Insect Identifica- report on the group for Illinois. tion. Previously, the Natural History Sur- This decision was strengthened by the vey had published a series of reports on the very apparent need for such a study of the insects of Illinois and, at the same time, had pseudoscorpions. Up to about 1930 the tax- developed the entomological collections. The onomy of this group in North America was double aim of the above reorganization in a preliminary and superficial stage. It was, first, to effect a well-balan.ed program was not until comprehensive analyses of the in the Survey's faunistic activities with the known world fauna were presented by J. C. hope that useful reports on the Illinois fauna Chamberlin and Max Beier in the 1930's would be made for groups other than insects that a groundwork was laid for modern and, second, to build up a comprehensive studies of the group. Since no detailed fau- reference collection of study material for nistic report has previously been prepared the identification of animal groups occurring for any region on the North American con- in the state. tinent, we hope that this Illinois report will A firm basis of expansion in several non- prove useful to many investigators. insect groups, such as the fish and mollusks. We are grateful indeed to Dr. Hoff for was provided several years ago by the ex- the identification of material and prepara- tensive Illinois collections of Stephen A. tion of the manuscript, and for contribut- Forbes. Robert E. Richardson, and Frank ing much of his own time to this project. C. Baker. Although in recent years certain Members of our staff in the Section of Fau- other groups, especially the arthropods and nistic Surveys and Insect Identification have reptiles, have been fairly well collected in contributed materially to the project. Sev- the state along with the insects, our collec- eral of them have assisted with the field pro- tions of many forms are at a beginning level. gram and with adaptation of the manuscript The general aim for all groups is now the to current Survey practices. Four total one that has been developed for the insects: views of pseudoscorpions were prepared to build up as extensive and inclusive a col- especially for this work by Dr. Carl O. lection of Illinois species as possible, and to Mohr, formerly Associate Entomologist and supplement this with representatives of other Artist. Mr. James W. Curfman assisted North American genera and species in each with the preparation, numbering, and letter- group. ing of the plates. Mr. Lewis J. Stannard, We feel fortunate in presenting this ac- Jr., Mrs. Leonora K. Gloyd, and Mrs. count of the pseudoscorpions of Illinois as Dorothy A. Moulton compiled the index and the first report of the expanded part of the assisted in assembling the Illinois records, program. In 194.? we began a co-operative preparing the bibliography, and checking and undertaking with Dr. C. Clayton Hof-f. then integrating the manuscript. at Quincy College, Quincy, Illinois, with the We have enjoyed throughout the help and view of investigating the pseudoscorpion co-operation of the Technical Editor, Mr. fauna of the state. At that time we were James S. Ayars, and Mrs. Drew S. Wetzel making extensive ground cover samples in and Mrs. Blanche P. Young of his staff. connection with certain insect projects, and Herbert H. Ross this activity dovetailed very well with a sur- Systematic Entomologist

CONTENTS

BIOLOGY 413

Feeding Habits.— Enemies.— Development. — Maturity ami Reproduction.

HABITAT PREFERENCES 415

Deciduous Forests.—Rock Outcrops.—Saml Dunes.—Swamps and Bogs.-— Domestic Situations. iDISTRIBUTlON 416

! Widely Distributed Species.— Southern Species.—Northern Species.—Other Species.

'collecting METHODS 418

PREPARATION OF MATERIAL 422

MORPHOLOGY 423

Body.—Appendages.—Genitalia.

ACKNOWLEDGMENTS 427

'classification 427

Disposition of Material.—Systematic List.

1 Key to Suborders 428

f.mwilies

Tridenchthoniidae 429

Chthoniidae 431

Ideoroncidae 444

Syarinidae 444

Neobisiidae 444

Menthidae 447

Olpiidae 447

Garypidae 447

Cheiridiidae 449

Sternophoridae 449

CHERNETmAE 449

Atemnidae 485

Cheliferidae 485

LITERATURE CITED 494

INDEX 497 of pseudoscorpion Ground cover or duff in woods such as these harbors a wide variety leaves should be brushed away and species. When a sample is to be collected, the dry top Samples from the lee ot a log the moist lower leaves and the top layer of soil scooped up. are often unusually productive. The Pseudoscorpions of Illinois

C. CLAYTON HOFF*

PSEUDOSCORPIONS are minute large series of many species and obtaining animals only a few millimeters long, for the first time what appears to be a fairly with the general appearance of di- accurate representation of the total fauna minutive scorpions except that they have no of Illinois. At the present time the list of tails. They belong to the large phylum of known Illinois species stands at 26. Un- joint-legged animals, the Arthropoda, and to doubtedly, other species will be found with the class Arachnida. which, in addition to additional collecting; the present study, the pseudoscorpions, embraces the spiders, based on over 5,000 specimens, represents mites, ticks, scorpions, and other related about .550 collections. groups. Pseudoscorpions are seclusive in The object of this report is twofold, first habit, occurring in soil cover and rotten logs, to present illustrated keys and descriptions under bark, and in similar places out of for the identification of species in this region, doors: one species is found in houses. In and, secondly, to summarize information their natural habitat, these little brown ani- regarding the distribution, biology, and habi- mals arc difficult to see. especially when they tat preferences of the species. As an aid in ilraw in their legs and "play possum." In use of the keys, a section has been included this position they look like little specks of on morphology, in which the structures now dirt. Probably because pseudoscorpions are considered of major taxonomic importance inconspicuous, few collections of the group are explained. have been made in the past, and the fauna, Summarizing the distribution has been at least of North America, and especially especially difficult because many identifica- of the central and north-central United tions made prior to Chamberlin's work are States, has remained scantily known. Prior probably incorrect and should be rechecked to the initiation of the present studies, only before they are cited. Because of this situa- one list was available for this region, that of tion there is little accurate information to Kwing (1911), which contained records of serve as a guide in foretelling what addi- six species from Illinois and two additional tional described species may be collected in species from neighboring states. Illinois. In order to make this report of Two factors have contributed to a con- wide application, the keys have been made siderable expansion of our knowledge of this to include all the genera known from the group for the Illinois region. The first central and northeastern portions of the factor was the work of J. C. Chamberlin United States and adjacent portions of and Max Beier, both of whom, about 19.50, Canada. made extensive contributions to the taxonomy of the world fauna of the pseudoscor- BIOLOGY pions, delineating the suborders, families, and genera clearly for the first time, and Available information on the development utilizing an abundance of new identification and habits of pseudoscorpions is meager and characters. The second factor was the de- is based chiefly on the study of a few large velopment of the Berlese funnel method of species, most of them of the suborder Mono- collecting pseudoscorpions and associated sphyronida. Scarcely any biological informa- small animals. This method, described on tion is available for the smaller forms be- page 418, has made possible collecting of longing to the suborders Diplosphyronida *Universlly of New Mexico, Albuquerque, N. \I. and Heterosphyronida.

[413] 414 Illinois Natural Histokv Survi;v Bullrtin lol. 24. Art. 4

Feeding Habits Enemies

Pseudoscorpions feed on small animals While pseudoscorpions prey upon smaller such as mites, ants, and a wide variety of animals, they are in turn the prey of larger other insects, as indicated by the many animals, especially birds, as indicated by the pseudoscorpions observed with such prey in frequency with which pseudoscorpion re- the chelae of the pedipalpi or palps. The mains are recovered from the digestive tracts pseudoscorpion's mouth, located on a tubular of birds. The part played in food cycles ap- structure called the rosirum, contains a pears to be the pseudoscorpions' claim to sucking structure, the pharyngeal pump, for ecological importance. taking in liquid food. The pseudoscorpion Development grasps its prey with the palps. These pre- hensile organs are supplied with a venom Pseudoscorpions have several distinct apparatus that efifectively kills or anesthe- stages in their life history: (1) the egg, in tizes the captured prey within a matter of most species carried by the female; (2) seconds. The palps and chelicerae, together the larva, in most species also carried by or singly, hold the prey to the mouth and the female; {?i) three stages of nymphs, the pseudoscorpion sucks the fluids from the which are free living; and (4) the adult. body of its victim. The pseudoscorpion female usually pro- The larger pseudoscorpions, especially duces only a small number of eggs, ranging Chelifer cancroides, make interesting pets. from 3 or 4 to as many as 30. The eggs One may be kept in a small corked vial in most species are not laid indiscriminately, into which is released a fly occasionally. but are simply extruded from the abdomen The pseudoscorpion will stalk the fly and retained as a group attached to the base patiently for a long time ; then suddenly it of the abdomen in contact with the external will reach out a palp and seize the fly. A genitalia. As the eggs are laid, they are good-sized house fly will put up quite a grouped in a single-layered rosette or around struggle, sometimes flying around with the the periphery of a spherical mass. In either pseudoscorpion attached; sometimes the case the egg mass becomes enclosed by a thin pseudoscorpion will be stretched out in mid- membrane. air, grasping the cork with one chela and the As young develop within the eggs, the fly with the other; but in a few moments the enveloping membrane is lost and the larvae battle is over, and the fly is completely quiet. assume positions with their heads toward Then the feast begins. the center of the rosette or spherical mass. Evidence to date indicates that no pseudo- Each of the first stage larvae has a sucking scorpions live as ectoparasites on larger apparatus for feeding, and rudiments of the! animals. Pseudoscorpions occur abundantly appendages, nerve ganglia, and other struc-i in mammal and bird nests, but apparently tures. The larvae secure a nutrient fluid they are not parasitic on the mammals or secreted from the maternal ovaries, whichi birds but instead feed on small arthropods become modified for this particular function.) in the nests. Species have been reported as During the period of larval developmen^f nipping man, but without inflicting any ap- the females of those groups in which tW

preciable injury (Beier 1932c/, 1941 ; Feio larvae form a single-layered rosette remai| 1941). active, while the females in which the larva* Large numbers of species have been re- are arranged in the form of a spherical mass ported from beneath the wings or elytra of have been observed to seal themselves in !i beetles, as well as from the bodies of other nest and remain inactive. The presence o: insects and birds, as described by Vachon large amounts of yolk in the eggs of a few (1940, 1947). These cases appear to be species (Essig 1929) suggests that the larvai nothing more than phoresy, with the pseudo- in these groups develop without attachmeH' scorpions feeding on mites and other soft- to the mother. bodied arthropods associated with the larger As development continues, a second larva flying insects and birds. Vachon forcefully stage is formed. In this stage, the suckin; expresses the idea that phoresy with few apparatus is atrophied and the larva ap exceptions is confined to the females. He parently lives on the food accumulated dur believes that phoresy is a response to in- ing the first or feeding stage of larval df sufficient food at a time when the females velopment. Also, during the second larvs are carrying and feeding the larval young. stage, the appendages and other structure lun,-. 1949 Hoff: Pseudoscorpions of Illinois 415

)f the nymph f;railiially make their appear- of the mating activity. During the period ance. of marked sexual activity and the courtship

At the end nf the larval development, the dance, a spermatophorc is released by the first nymphal stage or protonymph escapes male. Sperms from this spermatophorc are

From the brood pouch and begins to lead an picked up by the female. About 1 month independent life. The protonymph has es- after the transfer of sperms from the male sentially the same general appearance as the to the female, the eggs are extruded. iidult. T he continued development includes three molts, and the individual passes suc- HABITAT PREFERENCES .essively through the prrj/onymph, tleuto-

•lympli. and trilonymph stages, to form Pseudoscorpions have invaded many dif- finally the sexually mature adult stage. At ferent habitats in almost every part of the the time of each molt, the nymph secludes world. For the most part, the smaller forms itself in a silken nest for a period of 10 or live in debris and fertile soil, the larger 15 days, during which time distinct mor- forms under stones, under bark of trees, in phological reorganizations take place. The decaying vegetation, and abundantly in mam- various morphological changes that occur mal and bird nests. One genus, Giirypus, is Setween nymphal stages and between the found usually along the seacoast under tritonymph and the adult include the gradual stones and among algae and seaweeds. addition of tactile setae on the palpal chelae Some species of pseudoscorpions occupy and a gradual change in the shape of various very particular and restricted niches. The body parts, such as the segments or pod- habitat relationships of most Illinois pseudo- omercs of the appendages. The nymphal scorpions arc summarized below. A few stages of one Illinois pseudoscorpion, Apoch- species are omitted as a result of inadequate lli'/iiiiis tniiistus, have been discussed in ecological data. detail by Hoff (1946/1); the various stages Deciduous Forests of another species, ('htlioiiius lelrachelatus. have been described bv V'achon (1941fl, The abundant microhabitats found in the

1941/;). forest, fig. 1, afford the favorite living conditions for pseudoscorpions in Illinois. l"he -Vlaturity and Reproduction species inhabiting forest ground cover and Adult pseudoscorpions are undoubtedly decaying wood are among the most abundant fairly long lived, living probably for 6 months and widely distributed of our pseudoscor- to a year or two. This surmise is based on pions. collecting observations and notes made on a Three species have been found only in few individuals kept in captivity. Few exact ground cover and litter: Aprjchtlionius data over an extended period are available. mnestus, Heteroclitlioniiu mitllispinosiis. and

As is true of their relatives, pseudoscor- Miintlochthonius siiiiilersoni. Dactyloclu'liffr pions are dioecious. The males and females copiosus has been found in the same habitats, are similar in appearance. With the possible and one collection of this species was swept exception of a few forms, such as the genus from vegetation. Microbisium, in which the males have never Five species have been found chiefly in been found, they reproduce sexually; appar- rotting wood or under bark of logs and ently in the Microhisium females reproduce stumps: I'errucadithii spinosa, Lawpro- parthenogcnetically. cluriiis ablotujits, Diiioclu-irus pallidus. Pse- According to Beier (1932(/), mating takes liiphochffncs parvus, and Aciiminochernes especially place in the spring, during April and May, crassopalpus. The last two are debris of |but this information is based on the study of common in the rotten wood and jonly a few forms in the holarctic region and hollow trees. [possibly cannot be applied to species from Two species, Paracherncs squarrosus and lother areas. Unfortunately, information Microbisium confusum. are found both in in rotting logs and stumps; Irclative to mating is from observations of a ground cover and both habi- jfew species of Monosphyronida only, and Mirorhiruts iliiitdlus occurs in hollow iseneralizations cannot be made for the entire tats and also is conunon in cavities of order. In the few species that have received trees. chiefly oak jdetailed study (Kew 1912), the male and lindcr bark of livitig trees, liiiochcUfer nigripalpus. female perform a courtship dance as a part and hickory, occurs ;

416 Illinois Natural History Survey Bulletin J'ol. 24, Art. 4

Fig. 1.—Woods at Starved Rock State Park, Illinois. Wooded hillsides offer a wide variety of habitat niches: ground cover, rotten logs, hollow trees, moss, and root tangles. All these are prospective pseudoscorpion habitats.

Rock Outcrops rack bogs of the northern part of the state and in cypress swamps of the southern tip. Three species have been found associated with rock outcrops, fig. 2. These pseudo- Domestic Situations scorpions live in the debris and leaf mold on Chelifer cancroides is never found in the rock ledges or at the bases of outcrops. natural habitats removed from habitations Chthonius tetrachelatus has been taken in of human beings. Around man, however, it association with limestone outcroppings is widespread and abundant, occurring in Al undochthoiiius rossi and Larca granulata chicken houses, barns, dwellings, beehives, have been taken only around sandstone out- and nests of starlings and sparrows. croppings. Sand Dunes DISTRIBUTION Our only collections of Paisochelifer callus have been taken in grass and ground Pseudoscorpions are found in all parts of cover in sand dunes. the world except in the arctic and the ant- arctic regions. They reach their greatest and Bogs Swamps degree of development both in population Microbisium brunneum has been taken in numbers and in diversity of species in the Illinois only in the moss and debris in tama- tropics and subtropics. Many of the super- June. 1949 Hoff: Pseudoscorpions of Illinois 417

families or families are world-wide or nearly lind a few species in the nearctic region and world-wide in distribution, with at least a in the Atemnidae a few species outside of few representatives on nearly every large the distinctly tropical regions. Most of the land mass and with a concentration of closely family and subfamily groups have repre- related species on one or two of the conti- sentatives in a wide geographical area. nents. Thus, the diplosphyronld superfamily Such a widespread distribution appears

Neobisiidea is holarctic. while the heteros- interesting in a group without apparent phyronid Tridcnchthoniidae and monosphy- means of rapid dispersal. There are several ronid Atemnidae are typically circumtropi- possible ways, however, by which dispersal cal. In the Tridenchthoniidae, however, we may be accomplished. The small forms are

Fi^. 2.—Sandstone ledges in Starved Rock State Park, Illinois. Ory leaves and sparse grass accumulate on the ledges and in the crevices of these outcrops to form a thin, dry layer of organic material. A few animals, apparently especially adapted to these dry conditions, live here. One

of the denizens of these ledges is the Illinois pseudoscorpion Mundochthonius rossi. 418 Illinois Natural History Survey Bulletin Fol. 24, Art. 4 readily carried by air currents and even the been taken from only the southern tip of the larger species may on occasion be carried state. J'errucaditha spinosa has been found in this way just as are many of the insects only in the Mississippi River drainage area and spiders. Many forms are no doubt in the south-central and southern parts of transported by large insects and by mam- the state. mals and birds. Man may be an important Northern Species factor in distribution of some species, as indicated by the widespread domestic distri- To date Alundochthonius rossi has been bution of Chelifer cancroides, and by the found only in the northern fourth of the many specimens of other pseudoscorpions state. In the same category arc three other taicen from merchandise at quarantine sta- species that have been taken occasionally, tions along the seacoast (Chamberlin 1938). Dinocheirus pallidas, Dinocheirus solus, Whether any of these latter man-introduced and Paisochelifer callus. species have ever become established in a Other Species new area is not at present known. As with other animal groups, the Illinois Six species that have been collected in- pseudoscorpion fauna contains some species frequently are known from central or north- that are widely distributed and even cosmo- central counties in the state, from the vicinity politan, and others that are greatly restricted of Urbana, an area from which we have in their geographical ranges. It has seemed collected a large number of samples, or from worth while to group most of the species widely separated local areas. Similar in- taken in the state according to area of dis- tensive collecting in other areas may show tribution. The remainder are recorded from these species to have a much wider distribu- only one or two counties and the data relation in Illinois. The six species are Chtho- tive to distribution are possibly incomplete. nius ischnocheles, Lamprochernes minor,

It is possible that the rarity of some species Reginachernes ewingi, Reginachcrnes lyni-

is more apparent than real, and that the phatus, Larca granulata, and Chelanops { ?) apparent rarity results from greatly re- corticis. stricted habitat niches or from an insuffi- cient number of collections. Additional in- COLLECTING METHODS formation relative to the distribution records of the various species may be found in the Collecting of large pseudoscorpions, espe- systematic section of this paper. cially those belonging to the suborder Mono- sphyronida, may be done by hand from the Widely Distributed Species bark of trees and logs or by sifting soil, Ten species have been collected from a debris, and rotten wood. However, collect- sufficient number of Illinois localities to in- ing of most pseudoscorpions in these ways

dicate that they are widely distributed over is laborious and slow because of the low the entire state. These include some of our population density of some species and be- very common forms: Apochthonius moestiis, cause of the small size, seclusive habits, and Microbisium confusum, Lamprochernes ob- light color of other species, especially those longus, Parachernes squarrosus, Pselapho- of the suborders Heterosphyronida and chernes parvus, Acuminochernes crassopal- Diplosphyronida. piis, Mirochernes dentatus, Chelifer can- The most efficient method for collecting croides, Idiochelifer nigripalpus, and Dacty- pseudoscorpions is by the use of Berlese luchelifer copiosus. funnels, named after the Italian entomolo- Microbisium brunneum, associated with gist Berlese, who first used them exten- bogs or swamps, has been taken at the north- sively. A Berlese funnel is a very simple ern and southern extremities of the state apparatus, fig. 3, consisting of a fairly lony; but not in areas between. Among the species funnel suspended wide end up, with a screen infrequently collected, Chthonius tetrache- placed about a third of the way down the latus and Illinicliernes distinctus have been funnel, with heat applied either around the taken from northern and southern localities. upper portion of the funnel or over the top of the funnel, and with a container of pre- Southern Species servative, preferably 80 per cent ethyl alco- Two species, Heterochthonius multispin- hol, around the small bottom opening. Leaf osus and Mundochthonius sandersoni, have mold, bark scrapings, broken-up rotten June, 1949 Hoff: Pseudoscorpions of Illinois 419 wood, and other material suspected of har- half-inch mesh. Clumps of moss, leaves, sod, boring pseudoscorpions is placed on the and pieces of wood or bark are torn up by screen, the heat source is turned on, and hand into small fragments as they are put after a day or so the pseudoscorpions leave into the sieve ; then this material is raked the dried sample and migrate downward, over the sieve and shaken, the sifted materia! dropping into the preservative. being collected on a cloth or paper, fig. 4.

STEAM LINES CLOTH COVER

SCREEN SUPPORT

METAL SHADE

ETHYL ALCOHOL

Fig. 3.— Sketch of a Bcrlese funnel, showiiig a diagrammatic view across the middle. The central figure shows an arrangement for a steam coil, the lower left for an electric light. The Berlcse funnel provides the most efficient method for collecting pseudoscorpions and certain other animals.

Fig. 3 illustrates a funnel that has proved Pieces of wood or bark are knocked sharply very satisfactory; it is 15 inches from top to against each other to dislodge any animals bottom and the top has a diameter of 12 that might cling to them. The sifted mate- inches. The bottom opening, exactly seven- rial is then placed on the screen in the eighths inch in diameter, fits into a half-pint funnel and piled up around the sides to leave cream bottle, which makes an ideal container a small open space in the center of the for the preservative. Three angled brackets screen, fig. 5. This central opening allows or hangers are soldered inside the funnel to the easy migration of animals in the upper provide a rest for the screen, which is made part of the sample down into the bottom

of a quarter-inch or eighth-inch mesh hard- part of the funnel. The funnel so loaded is ware cloth; the mesh used depends upon the then placed in the rack for support, the bot- type of sample. A battery of several funnels tle with preservative is placed under the nar-

in a rack will allow the collector to sample row end, and heat is applied. Funnels in

a hundred pounds or more of material in position in rack are shown in fig. 6.

one operation. If steam is used as a source of heat, the

Samples of leaf mold or other material small copper lines that conduct it act as a are brought into the laboratory in cloth bags. partial support for the funnel by encircling Before being put in the funnel, each sample it about half way between the screen and is sifted carefully through a screen sieve of the top; a piece of cloth is tied tightly over 420 Illinois Natural History Survey Bulletin Vol. 24, Art. 4

bark and Fig. 4.—Sifting Berlese samples. Preparatory to putting material in the funnel, rotten wood are broken up and these and leaf mold sifted through a coarse screen. The sittings are put in the funnel.

the top of the funnel, fig. 3. If an electric toward the bottom, or the heat may kill an light or a choke coil is used for heating, it many of the organisms before they have should be hung directly over the center of opportunity to move out of the sifted ma- the funnel and no cloth tied over the top. terial. A little experience furnishes the best used. With a light or choke coil, it is often well to gauge of the intensity of heat to be use a wide reflector that approximates in An application of heat sufficient to dry the diameter the diameter of the top of the sample in 4 or 5 days is usually satisfactory. funnel. As the sample dries, the organisms move Care must be taken not to heat the sample out and downward, and finally drop into the too rapidly. Otherwise, moisture will con- bottle of preservative. dense in the lower part of the funnel and The Berlese funnel is extremely useful trap many of the animals working their way for collecting many animals in addition to June. 1949 HoFF: PSEUDOSCORPIONS OF ILLINOIS 421 pseudoscorpions: groups of beetles, particu- The following suggestions may prove larly Staphylinidae, thrips, Collembola, many helpful in picking up samples. For leaf mold groups of parasitic Hymenoptera, ants, milli- samples, scrape off and discard the dry sur- pedes, and centipedes, and a wide range of face leaves and scoop up the lower, rotted other minute animals that live in soil, sur- layers of leaves together with an inch or face cover, logs, or bark. two of the adjacent soil. You may en- Samples for the Berlese funnel may be counter especially good samples where leaves collected at any time of the year. If col- iiave blown in along the edge of a log (see lected during the warm months, they should frontispiece). In such a situation, take some be brought to the laboratory and placed in of the log bark with the sample. Collect the funnels within a day or two; otherwise rotten log samples in large hunks and break considerable loss of population occurs within them up in the sieve. From either standing the samples. If collected during the cold stumps or fallen logs in which the wood is months, they may be kept in cold storage still too hard to break up, collect the loose for a week or two with little loss. bark, as it is often quite productive. Fre-

Fig. 5.— Material to be sampled is placed on the sieve in the funnel and piled high around the edges; a small opening is left in the center. This arrangement allows an exit to the bottom for pseudoscorpions and other animals that might otherwise he trapped on top of the debris. 422 Illinois Natural History Survey Bulletin I'ol. 24, Art. 4

quently if you roll a log over, you may find usually dry out enough to permit sifting. animal runs under it; the debris and earth Allow winter samples to thaw and dry be- under and around these runs, together with fore you sift them. animal nests, frequently give unusual catches. PREPARATION OF MATERIAL Probably the most productive single type of sample is that taken from the interior of Most of the characters used in the iden- a standing hollow tree. At the bottom of the tification of pseudoscorpions can be seen only hollow you may find a foot or more of fine, in proper orientation of the specimen and rotten, woody material that you can scoop under moderate to high magnifications. For out by reaching through a break in the base this reason it is necessary to prepare pseudo- of the tree. A 50- or 60-pound sample of scorpion specimens carefully so that they this is almost sure to net many interesting may be studied under the compound micro- forms. Occasionally you may collect a wet scope. sample, such as sod from a marsh or debris The following method has been found from a stream edge. If you allow it to very satisfactory. First, remove from the remain in the sack for a few days it will animal the two chelicerae, the two palps,

Fig. 6.— Funnels in position on rack. In this assembly, each funnel rests inside a double ring of copper tubing (as on funnel at extreme lower left) through which flows live steam.

The steam produces the heat that dries out the sample and drives the animals out of it. Cotton or a small rag is tamped between the end of the funnel and the bottle of preservative to prevent escape of specimens. Jun,'. mo Hoff: Pseudoscorpions of Illinois 423

one of the first, and one of the fourth legs. mounting some species or stages that are Leave these in alcohol while the rest of the only lightly sclerotized, stain the body in

body is being treated. Next, puncture the acid fuchsin. Wash the material in dilute

body by making a slitlike cut in the side of hydrochloric acid before putting it into this

the abdomen; then place it in a 10 per cent stain. After staining, wash the preparation solution of potassium hydroxide. This step in distilled water for some time to bleach

is intended to dissolve the muscles and in- out excess stain; then clear it in beechwood ternal organs. Soak the body in cold hy- creosote and mount as directed above. droxide solution for several hours, or in hot Label all slides clearly, indicating collec- solution (heated in a boiling water bath) tion data and means of associating slide ma- for a few minutes. The exact amount of terial with similar material in fluid. When time will depend upon the size and darkness an organism is identified, its name should of the specimen and can be gauged after a he put on the slide label.

little experience. The object is to clear the preparation in hydroxide long enough to dis- MORPHOLOGY solve out the internal material so that the preparation will be transparent, but not long As an aid in the use of keys and the accu- enough to cause marked bleaching or de- rate identification of species, the important coloration of the parts. After soaking the features of the external morphology of

preparation in hydroxide, remove it to dis- pseudoscorpions are outlined below. Addi- tilled water and squeeze out the disinte- tional information is available in the works

grated viscera by gentle pressure with needle ot Chamberlin (1931^), Beier ( 1932A, r, or forceps. Alternately press and release the ,1), and Roewer (1936, 1937). abdomen several times; this manipulation Body will cause a pumping action that will remove

most of the internal material. Allow the The body of a pseudoscorpion, fig. 7, is preparation to soak in a fresh water bath divided into two general parts, the cephalo- for about a day to remove the last traces of thorax and the abdomen. Both the body dissolved material. After the washing proc- and the appendages bear many setae, the ess, dip the body in 1/50 normal hydro- number and arrangement of which are of chloric acid to neutralize the remaining considerable taxonomic importance. In

hydroxide, and put it in 70 per cent alcohol. many species, the setae are slender and Next place the cleared preparation and the tapering, but in others they are modified in appendages previously removed in beech- various ways. Commonly some of the setae wood creosote. After they have completely are divided or branched at the tips and give cleared and dehydrated, mount them in somewhat club-shaped silhouettes; these Canada balsam or clarite. setae are spoken of as clavate or subclavate In mounting the specimen, place the body in allusion to their general appearance. In with the ventral side uppermost and the two some cases the branching occurs on only one palps under one cover located a little to side of a seta, and in others it extends down the left of the center of the slide, with suffi- both sides of the seta to give a feathered cient room for the slide label to the left of effect. The cephalothorax is covered dor- the cover. Mount one of the palps with the sally by a shield or carapace that is with- dorsal side uppermost. Remove the chela out segmentation, although in some cases from the other palp and spread the fingers one or two transverse furrows subdivide the wide apart. Mount this chela with the ex- surface of the carapace. ternal or lateral surface uppermost. If the The mouth is at the anterior end of the body and palps are heavy and thick, support cephalothorax and the feeding structure is the cover glass with short pieces of capillary retracted within a cavity in the anterior tubing or short pieces of finely drawn glass portion. In most species, one or more pairs rod. -Mount the chelicerae and the previ- of eyes are situated on or near the lateral ously removed legs under a smaller cover to margin of the cephalothorax; each eye has the right of the first. Do not use supports a single facet. under this cover since the cover glass should The abdomen consists of 12 segments, of rest on the legs and press them out flat for which the last is greatly reduced and very measuring. inconspicuous. In some species, as indicated

After clearing with hydroxide and before in fig. 7, the eleventh and twelfth segments 424 Illinois Natural History Survey Bulletin Fol. 24, An. 4

cannot be seen in strict dorsal view. Each abdomen laterally between the sternites and segment of the abdomen bears a dorsal ter- tergites. gite and a ventral sternite, but in many Appendages forms each of these is divided medially to form lateral sclerites or areas called tergal A pseudoscorpion bears six conspicuous and sternal halves. The chaetotaxy and pairs of segmented appendages, all arising sculpturing of the tergites and sternites are from underneath the cephalothorax: a short often useful in taxonomy. The tergites are pair of pincer-like cheliccrae; an elongate usually regular in arrangement and shape, pair of palps, each ending in a pincer-like but the anterior sternites are modified as a structure; and four pairs of legs, designated result of the presence of the genital opening in descriptions by Roman numerals. Unlike and its accompanying structures. Toward most of the members of the Arachnida, the the lateral end of each third and fourth pseudoscorpions lack patellae on their

sternite is a stigma or spiracle through appendages. which air is taken into the tracheal system. Ghelicerae.—Each chelicera, fig. 8, is In the males of a few species, the lateral attached near the anterior end of the ends of some of the tergites are modified to cephalothorax and consists of a basal seg- form keels. A pleural membrane covers the ment or podomere extended anteriorly to

Fig. 7.—Sketch of a heterosphyronid pseudoscorpion to show the general body plan and appendages. The Arabic numerals designate segments of the abdomen; the Roman numerals indicate the four walking legs which arise from under the carapace on the venter of the cephalothorax. Abdominal segments 11 and 12 are not visible in a dorsal view of all species. chelal finger; movable chelal finger; Abbreviations used are c/i, chela; fe, femur; jf, fixed mf, mt, metatarsus; pb, pars basalis; pt, pars tibialis; ta, tarsus; ti, tibia; Ir, trochanter; tt, telotarsus. The coxa, which is basad to the trochanter on each leg, is not shown. — —

June. I'M'J Hoff: Pseudoscorpions of Illinois 425

form a fixed finger and a second segment to spicuous galea or spinneret is attached near form a movable finger. The dorsal surface the end of the movable finger. This galea

of the base of the chelicera bears numerous is said to function in spinning silk discharged setae. T hose that are of major significance from silk gland ducts that open at the tips

, — serrulr exterior

flagellum

Fig. 9. Chelifrr cancroides 9. Lateral 8. Fig. Lamprni hernrs ohlnnyiu $ . Ex- view of chelal hand of palp. The standardized terior or \'iew dorsal of chelicera. The setae symbols used for the tactile setae of the mov- important in taxonomy are indicated by the able finger are as follows: b, basal seta; sb, standardized (iesignations: b, basal seta; es, subbasal seta; st, subterminal seta; /, terminal exterior seta; ijs, galeal is, seta; interior seta; seta. On the fixed finger, e indicates exterior /.(, laminal seta; sh, subbasal seta. and / indicates interior; either is used in con-

nection with /, sh, and the like. Thus, et is the

exterior terminal seta, while // is the interior in taxonomy have been designated by letters terminal seta. as shown in fig. 8. The setae vary among species and genera in number, position, and size. The lateral margin of the subventral of the galeal branches or rami. When the surface of the cheliceral base bears a flagel- galea is reduced or wanting, the ducts ap- lum that consists of a few to many modified pear to terminate in a tubercle or directly on setae. The fixed finger is usually smaller the surface near the tip of the finger, fig. than the movable cheliceral finger, bears an 25 6\ apical tooth and several denticles along the Palps.—The palps, fig. 7, are the most iimer margin, and is supplied with a longi- conspicuous appendages of the animal and tudinal row of plates making up the serrula are usually extended anteriorly. Each palp interior. With exception of the terminal consists of several segments or podomeres: three or four, the plates are frequently fused the coxa or maxilla, the trochanter, the to form a so-called velum. The outer mar- femur, the tibia, and the chela. The chela gin of the fixed finger often bears a longi- has a movable finger that no doubt repre- tudinal keel or riblike structure known as sents an additional segment. The character- the lamina exterior. The movable cheliceral istics of the palpal segments most useful in finger has a prominent serrula exterior, con- taxonomy arc the general shape, the chaeto- sisting of a row of ligulate plates extending taxy and sculpturing, the absolute size, and along nearly the entire length of the finger. the length-width ratio. The last is fairly The movable finger terminates in an apical constant within each species and use of it is tooth and the inner margin bears either a becoming increasingly important for the subterminal lobe or a series of denticles. separation of closely related species. The

Near the end of the movable finger is in- segments of the palp, especially the chela, serted a galeal seta. In some groups, a con- in some cases show sexual dimorphism, the —

426 Illinois Natural History Survey Bulletin Fol. 24, Art. 4

chela of the male frequently being larger rigidly attached to the cephalothorax and and stouter than that of the female. can easily be seen in ventral view. In some

The characteristics of the chela, fig. 9, groups of the Heterosphyronida, one or are very important in classification. For a more of the pairs of coxae bear spines. satisfactory study of the chela, a side view Some species have a minute seta-bearing must be obtained. In such a view, the inner tubercle located medially between the third margins of both the fixed and movable and fourth pairs of coxae. fingers in most cases seem to be supplied Genitalia with small contiguous teeth. In some cases, however, the teeth are alternately large and In addition to the structures already de- small, or variable in different parts of the scribed, the genital organs are of some im- margin. In the family Chernetidae, acces- portance in taxonomy. The external geni- sory teeth are borne on the outer and inner talia are located on the ventral surface of aspects of each finger near the marginal

teeth. Great taxonomic significance is attached to the number and arrangement of atrium

the tactile setae of the fingers. In most coxal sac species of pseudoscorpions the fixed finger coxa IV has eight tactile setae and the movable finger

has four, as shown in fig. 9. In other species,

the number of tactile setae is greater or

smaller. Each tactile seta is identified by the bulbous structure or areola from which

it originates. One or both of the chelal fingers terminate in a venedens, or venom 10. tooth, through which the venom is dis- Fig. Dactylocliclifer coplosus i . Im- charged. The venom duct can usually be portant structures of the male genital complex of the highly specialized type found in the traced proximally to the nodus ramosus, a Cheliferidae. dilation at the point where the small ducts form individual venom glands or reservoirs unite to form a single duct. the abdomen in the region of the second and Legs.—With respect to the legs, several third abdominal segments. The second characteristics such as the number of seg- sternite forms an anterior genital operculum, ments, the nature of the joint between the and the third sternite forms a posterior pars basalis and the pars tibialis of the operculum. femur, and the nature of the terminal claws In the female, the genital complex is

and chaetotaxy are important in classifica- relatively simple. When better known, it tion. The number of segments in the legs will probably assume greater significance in

is used as the basis for dividing the order classification. In some species, a pair of Pseudoscorpionida into three suborders. In seminal receptacles may be distinguished. the suborder Monosphyronida, each leg has These are often in the form of elongated six apparent segments: coxa, trochanter, tubules. In many females, perforated plates, pars basalis and pars tibialis of the femur, known as cribriform plates, are present. The tibia, and tarsus. In the suborder Diplos- shape, position, and number of these plates phyronida, the tarsus of each leg consists of are characters used in systematic work. The the proximal metatarsus and the distal seminal receptacle and the cribriform plates telotarsus, so that the leg appears to be may be seen in many females cleared with made up of seven segments. In the suborder hydroxide.

Heterosphyronida, each first and second leg In the male, the genital complex is more has a single tarsal segment, whereas each variable than in the female. The chaetotaxy third and fourth leg has two tarsal segments. of the opercula can be used on occasion The nature of the legs in the heterosphyro- as a specific character. In one group, the

nid pseudoscorpions is shown in fig. 7. In subfamily Cheliferinae of the family Cheli- general, the legs do not show sexual feridae, the genital organs of the male are dimorphism except occasionally in modifica- highly modified and specialized, fig. 10. In tions of the tarsal claws of the first leg. males of certain genera of this group, each The coxae of the legs are more or less fourth coxa contains a coxal sac either with Jinu, 1949 Hoff: Pskl'doscorimons of Illinois 427 or without a separated medial portion known College, Fort Collins, Colorado, and com- as the atrium. The sclerotized statumen pleted while he was at the University of convolutum may or may not be invaginated New .Mexico, Albuquerque, New Mexico. anteriorly. When an anterior invagination Deep appreciation is extended to these insti- occurs, the invagination contains a short tutions and their officials for facilities and sclerotized rod. time, without which this project could not have been completed. This study was aided ACKNOWLEDGMENTS also by a grant from the American Associa- tion for the Advancement of Science through This investigation has been made possible the Illinois State Academy of Science. by the encouragement, co-operation, and assistance of many persons and organizations CLASSIFICATION interested in the fauna of Illinois. Co-operative effort has resulted in the accumulation The order Pseudoscorpionida or Chelone- of a greater number of collections of pseudo- thida, embracing all of the pseudoscorpions, scorpions than has ever been previously is set of^ from other orders of the class massed together at one time from any one Arachnida by the following combination of state. The total number of collections made characters: carapace unsegmented, fig. 7, available for this study is about .?50, of covering the cephalothorax ; abdomen seg- which two-thirds are from the collections mented, not divided into pre- and post-abdo- of the Illinois Natural History Survey. men ; no sting on the abdomen ; chelicerae Pifty-seven collections were taken by the small and chelate; palps large and chelate; writer. Other collections were loaned by icspiration by means of simple tracheae. the Illinois State Museum, the Chicago The order is divided into three suborders,

Natural History Museum, the American each of which is represented in the fauna Museum of Natural History, the Museum of Illinois. These suborders in turn are of Comparative Zoology, and the Cornell divided into a system of superfamilies, fami- University Museum. The two museums lies, and lower categories in order to facili- last named made available type specimens tate grouping together related genera and and material collected and recorded from demonstrate as far as possible natural rela- Illinois by H. E. Ewing. tionships. The general classification fol- The writer wishes to acknowledge the as- lowed here is that outlined summarily in sistance of the following persons who either papers by Chamberlin {\929b, 1930, 193Ifl) collected pseudoscorpions or aided in some and extended or modified by Beier (I932A, other way toward the completion of this f, i7). These papers as a group give a com- study: Dr. H. H. Ross, Dr. T. H. Prison, prehensive outline of the classification of the Dr. H. B. Mills, Dr. M. W. Sanderson, entire pseudoscorpion world fauna, to- Dr. M. -M. Leighton. Dr. A. E. Emerson, gether with full bibliographic treatment of Dr. and -Mrs. Clarence Goodnight, Dr. the supergeneric names involved. Material

Heinz A. Lowenstam, Dr. W. J. Gertsch, in these papers is not repeated in the present Prof. Nathan Banks, Dr. H. J. Van Cleave, paper, but instead the interested student is Dr. V. E. Shelford, Dr. Carl O. Mohr, Dr. referred to them for further study. Kathryn M. Sommerman, Rev. Edbert The bibliographic citations given in the Long, Rev. Robert Brinker, Dr. C. L. present paper for species or genera are not Remington, Mr. Willis E. Snow, Mr. and intended to be complete. They consist of Mrs. W. V. Rapp, Jr., Dr. B. D. Burks, references to the original description, to

•Mr. Ciilbert M. Wright, Mr. Lewis J. papers in which are given diagnoses more Stannard. Jr., and Mr. Henry Dybas. The nearly complete than the original, to publica- writer's sincere appreciation is especially tions that contain important changes in tax- extended to Dr. J. C. Chamberlin for infor- onomic position or nomenclature, and to mation from his personal files of unpublished papers that have definite reference to the data and for the loan of specimens from his fauna of Illinois. personal collection. In this paper a complete diagnostic charac-

This study was carried out chiefly while terization of a species is given only for the writer was employed at Quincy College, species that arc new or for which no recent Quincy, Illinois, continued while he was at and complete description is available in the the Colorado Agricultural and Mechanical literature. Kor other species, a summary of .

428 Illinois Natural History Survey Bulletin Vol. 24. Art. 4

diagnostic characters is given and reference Subfamily Neobisiinae made to available extended descriptions. Microbisitim brunneum (Hagen) Measurements throughout this paper are Microbisium confusum Hoff in millimeters. Family Garypidae Larca granulata (Banks) Disposition of Material Suborder MONOSPHYRONIDA Most of the Illinois material recorded Family Chernetidae here and not otherwise noted is in the col- Subfamily Lamprochernetinae lection of the Illinois Natural History Sur- Lamprochernes oblongus (Say) vey at Urbana, Illinois. Some material that Lamprochernes minor new species belongs to other institutions is cited, and this Subfamily Chernetinae usually is indicated by letters following the Parachernes squarrosus new species record. The letters used are as follows: Pselaphochernes parvus Hoff CH—Collection of C. Clayton Hoff, Uni- Regiiiachernes ewingi new species versity of New Mexico, Albuquerque, N. Reginachernes lymphatus new species Mex. Dinocheirus pallidiis (Banks) new com- CM—Chicago Natural History Museum, bination Chicago, 111. Dinocheirus solus new species cr—Collection of C. L. Remington, Yale Acuminochernes crassopalpus (Hoff) new University, New Haven, Conn. combination cu—Cornell University, Ithaca, N. Y. Mirochernes dentatus (Banks) HV—Collection of H. J. Van Cleave, Uni- lUinichernes distinctus new species versity of Illinois, Urbana, 111. *Chelanops (?) cor^/f/f Ewing IM— Illinois State Museum, Springfield, Family Cheliferidae 111. Subfamily Cheliferinae

jc—Collection of J. C. Chamberlin, For- Tribe Cheliferini est Grove, Ore. Chelifer cancroides (Linnaeus) MCZ—Museum of Comparative Zoology, Idiochelifer iiigripalpus (Ewing) Harvard College, Cambridge, Mass. Paisochelifer callus (Hoff) ws—Collection of Willis E. Snow, Ur- Tribe Dactylocheliferini bana, 111. Dactylochelifer copiosus Hoff The keys to suborders, superfamilies, and Systematic List families are designed to accommodate the entire fauna known at present from America To date there are Illinois records for 26 north of Mexico. Where used, the subspecies of pseudoscorpions. Of these, two family keys are designed for the same fauna. are known only on the basis of literature Keys to tribes and genera are intended pri- records. They are indicated by an asterisk marily to resolve the fauna of the central in the following list. and eastern United States and adjoining portions of Canada. Keys to species include Suborder HETEROSPHYRONIDA those taken in Illinois and in addition a few Family Tridenchthoniidae species that are known from surrounding Subfamily Tridenchthoniinae states and that ultimately may be found in Tribe Verrucadithini this state. Ferruca/lltha spinosa (Banks) Family Chthoniidae Key to Suborders Subfamily Chthoniinae 1 Each first and second leg with five segments Tribe Chthoniini exclusive of the coxa, and each third *Chthonius ischnocheles (Hermann) and fourth leg with six segments ex- Chthonius tetrachelatus (Preyssler) clusive of the coxa, fig. 7 Apochthonius moestus (Banks) Heterosphyronida, p. 429 Heterochthonius multhpinosus Hoff All legs with the same number of segments Mundochthonius rossi new species 2 Mundochthonius sanderson't new species 2. Tarsus of each leg divided into metatarsus and telotarsus, so that the leg has six Suborder DIPLOSPHYRONIDA segments exclusive of the coxa Family Neobisiidae Diplosphyronida, p. 443 —

]')4') Jinu . Hoff: Psfl DoscoRi'ioNs oi' Illinois 429

Tarsus of each leg not divided, so that the leg has five segments exclusive of the coxa Monosphyronida, p. 449

Suborder HETEROSPHVRONIDA

Members of this suborder may be recognized by tile single tarsal segment in the first and second legs and the two tarsal segments in the third and fourth legs. Hoth families represented in North America are known from Illinois. Both may be recognized by the extremely large chelicerae, fig. II, as well as by the key characters.

Key to Families

Most abdominal tergites with a double row of closely spaced, short and stout setae extending completely across each segment; Fi>;. 11. poilithnnlus moestus. an respiratory spiracles of third and fourth A example of the suborder Hetcrosphyronida and the sternites oblicjuely placed and with differ- fainilv Chthoniidae. entiated guard sclerites, fig. 12£; body and palps very setose and granular; spines on

coxae I and II, fig. 12D -Members of this genus possess movable Tridenchthoniidae, p. 429 chelal fingers on which the marginal teeth Abdominal tergites with only a single row ot are broad, rounded, and contiguous. Only long and slender setae across each segment; one nearctic species is respiratory spiracles of third and fourth known. sternites transversely placed and without guard sclerites differentiated from the ster- Verrucaditha spinosa (Banks) nites, fig. 15D; body and palps no than more Clithonius spinosus Banks (1893, p. 67). weakly granular; Illinois species with spines I'lrruiaditha spinosa (Banks). Chamberlin on coxa I, (ig. II, 15C, on coxa or on coxae (1929A, p. 59), Chamberlin & Chamberlin II and III Chthoniidae, 431 p. (1945, p. 24), Hoff (1946/;, p. 103). In general, the following combination of TRIDENCHTHONIIDAE characteristics serves to identify adults without mounting: body length 1.0-1.3 mm.; Pscudoscorpions belonging to this group carapace with about 100 heavy lanceolate in- can be recognized by the obliquely placed vesting setae, fig. \2B, and with the anterior stigmata or respiratory spiracles, fig. 12£, c;:rapacic margin distinctly bilobed ; the pair that arc guarded by well-developed sclerites. of tactile setae on the dorsum of each chelal Some exotic genera have only a single row hand removed from the proximal margin of of stout setae across the abdominal tergites. the hand by about one-fourth its length, figs. In America north of Mexico the family is \2A, \2C; spines on coxae I and II, fig. \2D. represented by a single genus, J'errucailitlui. Vox more extensive descriptions of this Diagnosed in relation to the world fauna species, the reader is referred to Chamberlin by Chambcrlin & Chamberlin (1945), this & Chamberlin (1945)' and Hoff (1946i). genus is placed in the subfamily Tridench- Deutonymph.—The following descrip- thoniinae and tribe X'errucadithini. tion is based on one individual. This stage has not been described previously in the 1. VERRUCADITHA Chamberlin literature. The deutonymph in general resembles the adult, length 0.82 mm., great- Alura Chamberlin (1926, p. 334). Genotype, est width of abdomen 0.35 mm. Carapace by original designation : Clithonius spinosus anteriorly bilobed, each lobe Banks. (Name preoccupied by Alma Mnes- with four stout chler 1883.) marginal setae; eyes conspicuous. Chelicera I'crrucaditlia Chamberlin [19291;. p. 59), New very similar to that of the tritonymph as name for Alura Chamberlin. previously reported (Hoff I946i) except ferruiaJitha Chamberlin. Chamberlin &: that there are three rather than two galea- Chamberlin (1945, p. 22). likc processes near the end of the movable — — —

430 Illinois Natural History Survey Bulletin Vol. 24, Art. iL^UJk

Fig. 12. I'crrucaditha spinosa. A, dorsal view of palp 5 ; B, setae of carapace ; I

exterior view of chela, 3 ; O, coxal spines, 5. £, stigmata or respiratory spiracles, 9.

finger and 10 rather than 14 plates in the This species usually occurs in debris ar

scrrula exterior. Three to five spines occur decaying wood of old stumps and logs i on each of coxae I and II. Segments of palps deciduous forests. One collection was take weakly granulate and light yellow in color. from "ground cover" and one from falle Palp with femur 0.205 mm. long, 0.07 mm. needles under an eastern redcedar tr« wide; tibia 0.125 mm. long, 0.075 mm. wide; {J uniperus virginiana Linnaeus). chela 0.4 mm. long, 0.082 mm. wide; depth of hand equal to width, length about 0.13 mm. ; movable finger 0.26 mm. long. Fixed chelal finger with seven tactile setae, ds and et near distal end, it and est near center, two setae near base of finger, and one {isb or ib) a little proximad to the mid-point of the dorsum of the hand; movable finger with two tactile setae near center. Marginal teeth similar in appearance to those of the adult; movable finger with 24 marginal teeth ; fixed finger with 1 1 acute and well- separated teeth in the distal half of the finger and 10 more nearly contiguous teeth on the proximal half of the finger margin.

Distribution . Verrucad'itha spinosa dues not occur abundantly in Illinois. Of eight records, four are from Adams County and one each from Brown, Jackson, Jersey,

and Madison counties. The species is widely distributed in the central and southeastern part of the United States as shown by exist- ing records (Chamberlin & Chamberlin Fig. 13. Chthonius ischnocheles. Laters 1945). view of chela. (After Chamberlin.) — —

/««,-. VU9 Hoff: Pseudoscorpions of Illinois 431

Illinois Records. Adams County: 194.'!, CHTHONIIDAE

::. C. Hoff, 1 i ; Coe's Spring, Oct. 28, 1944, Rev. Edbert Long, \ i ,29 (1(},19,ch). Species belonging to this family may be Edwardsville: Sept. 24, 194.?, Ross & San- recognized by the transversely placed spi- icrson, I immature. Gr..\fton : Sept. .^0, racles that are not accompanied by separate

194,?, Ross I & Sanderson,

)ct. 12, 1933, Frison & Ross, 1 $ . Quincv: genera belong to the subfamily Chthonjinae outhwest of, 1944, July 8, C. C. Hoff, 1 and the large tribe Chthoniini. Members of inmature (ch); south of, July 8, 1944, C. this tribe possess two tactile setae (isb and .'. Hoff, 1 i . Siloam: Siloam Springs, Aug. /A), figs. 14/:/, 15/^, in a transverse pair on !9, 1945, C. C. Hoff. 1 immature (ch). the dorsum of each chelal hand.

Fi)!. 14. Clitlionius telnu/irltilta. A, dorsal view nf palp, i \ B, external view of chela, C, first ! ; leg, i ; D, parts of coxae 11, III, and IV, showing the spines of coxa III and the ubercle /•', and setae, 9 ; £, two isolated coxal spines enlarged to show structure, i ; fourth

:g, i , drawn to a much smaller scale than first leg, C. If the specimen is shrunken in mounting, be tubercle and setae in D are difficult to see. —

432 li.i.iN'Ois Natural Historv Survkv Bulletin

<>'' a i' Vi ¥ ^ -VV-ft^

15. Fig. Apoc/ilhonius mocstus. A, palp in dorsal view, $ ; B, chela in lateral view,

9 ; C, spines of coxa I, 'i \ D, stigma on sternite 3, 9-

Key to Genera on the mesal portion of coxa II, figs. ( 17D, 5. Mundochthoniusi Eyes absent; body length 2.3 mm 18D 6. Genus? packardi Eyes present, or, if wanting or vestigial, 2. CHTHONIUS C. Koch body length less than 1.5 mm 2

Mesal portion of coxa I containing a group Chthonius C. Koch (1843, p. 76). Genotype, i of well-separated spines, often in a row, by subsequent designation of Simon (1S79): each spine arising from an elongate slit, Obisium orthodactylum Leach. fig. 15C; intercoxal tubercles not present Chthonius C. Koch. Chamberlin (1925/.', p. on the mid-line between any of the 69), Chamberlin (1931fl, p. 212), Beie^^ coxae 3 (1932*, p. 43).

Mesal portion of coxa I without such The genus Chthonius is characterized by> spines; instead a comb of short spines the presence of an intercoxal tubercle, spineS'' or a group of short, feathered spines on coxae II and III, and simple teeth (not' present on the mesal region of coxa II or always contiguous) on the inner margins of coxae II and III, figs. 14D, 17£; a Several minute intercoxal tubercle bearing two the chelal fingers, figs. 14B, 14Z). small setae present between the junc- subgenera have been outlined in the liter- tion of coxae III and IV 4 ature. Of these subgenera, two are repre- Teeth along margins of chelal fingers short sented in Illinois, each by one species. Other and broad, arranged close together, species in the genus are known from fig. 155 3. Apochthonius Georgia, North Carolina, and California. Chelal teeth widely spaced, alternately large and small, fig. 16C Key to Subgenera and Species 4. Heterochthonius A group of well-separated, short, feathered Teeth of inner margins of chelal fingers largg spines present on each mesal margin of acute, uncrowded, and somewhat conies^ coxae II and III, figs. 14£, 14D and recurved; chelal hand appearing evenlj 2. Chthonius rounded on the dorsal margin as viewed" Short coxal spines in the form of a comb, from the side, fig. 13. Subgenus ChlhoniuSi frequently united at bases, present only ischnocheles< June, 1949 Hoff: Pseudoscorpions of Illinois 433

Teeth o( inner margin-, of cheial lingers long Subgenus Ephippiochthonius Beier and pointed, often well separated; in lateral Ephippiochlhonius Beier (1930a, p. 323). view, the chelal hand displays a depression Genotype, by present designation: Scorpio between the tactile seta of the dorsum of the tetrachelatus Preyssler. hand and the linger base, fig. \AH. Subgenus Ephippiochlhoniiis tetrachelatus Members of this subgenus are recognized by the presence of 18 setae on the carapace, Subgenus Chthoniiis C Koch of which two are on the posterior margin; in lateral view, the chelal hand displays Clilhonius s. sir. C. Koch. Beier (1932A, p. 47). a depression between the tactile setae of the Members of this subgenus may be recog- dorsum of the hand and the finger base, nized by the lar^e. acute, and retroconical fig. 14/i; teeth of chelal fingers are long, pointed, (pointin;: toward the base of the finirer) and usually well separated. A single species marfiinal teeth of the chelal fingers. The has been taken in Illinois. marginal teeth in some species arc well separated, at least in the distal part of the fi.\ed Chthonius tetrachelatus (Preyssler) finger. The chelal hand has an evenly Scorpio tetrachelatus Preyssler (1790, p. 59). rounded contour as viewed from the side, Chthonius tetrachelatus var. maeulatus Menge. there being no dorsal depression near the Stecker (1875. p. 314). base of the fixed finger. single A species of Chthonius lonijipalpus Banks (1891, p. 164). the subgenus has been taken in the Illinois Chthonius lonyipalpus Banks. Ewing (1911, fauna. p. 80). Chthonius tetrachelatus (Preyssler). Vachon Chthonius isclinocheles (Hermann) (1941a, p. 442). Chthonius (Ephippiochthonius) tetrachelatus V.hrlifcr isclinocheles Hermann (1804, p. 110). (Preyssler). Hadzi (1933a, p. 139; 1933/', Chthonius PensyU'anicus Hagen (1869. p. p. 179), Hoff (1946A, p. 109). 52). Chthonius prnnsylvanicus Hagen. Ewing Individuals of this species may be recog- (1911, p. 80). nized by the characteristics given in the key. Chthonius ischnoeheles (Hermann). Cham- especially by the shape of the chelal hand

berlin (1929/', p. 71 ). and the nature of the marginal teeth of the Chthonius (Chthonius) ischnoeheles (Her- chelal fingers, fig. I4B. No detailed descrip- mann). Beier (1932*, p. 48). tion is included here, since the species has been The species can be recognized from the treated recently and adequately by Hadzi rharacters given in the keys. The following (1933a, 19334)' and Vachon (1941a, 1941/-). idditional characters are listed by Beier The adults and most nymphs (but not the (I932A). Ccphalothorax with 20 to 24 protonymph) in our collections agree well setae, the posterior margin with four to with those described by \'achon, except that iix equally long setae. Setae of the tergites: the palpal segments of our specimens appear ^:4:4:4:6:6:6:6. Marginal teeth of the pal- to be a little more slender than indicated in )al lingers pointed, triangular in outline, \'achon's drawings. ind directed somewhat toward the base of I have examined a single protonymph he finger, fig. 13. Teeth of movable finger that apparently belongs to this species. Un- ilmost as strong as those of the fixed finger. fortunately, this protonymph was not asso- Joxa II with at least 14 spines, coxa III ciated with adults and, as a result, the identi- vith at least 9 spines. Intercoxal tubercle fication may be questioned. The individual vith two setae. Body length 1.6-2.4 mm.; dififers railically from the form described by )alpal hand 0.5 mm. long, 0.27 mm. wide; \'achon (1941a, 1941/») as the protonymph inger length 0.85 mm. of tetrachelatus. Possibly V'achon studied Distribution.—Ewing (1911) reported a the last larval stage rather than the first ingle individual of this species from Hill- nymphal stage, or protonymph, since his •ry, Vermilion County, Illinois. No addi- drawings do not appear to be made of ani- ional collections have been secured in our mals sufficiently developed to be proto- ecent survey. The species has a wide dis- nymphs. Because of limited material and ribution and is reported from many locali- questionable identification, the protonymph ies in Europe and from the northeastern I have examined that apparently belongs to "art of the United States (Chamberlin this species is not described here. .929i). More Illinois records of this species Distribution.—C.hlhotiius tetrachelatus vould be useful. « as taken by the writer in 1 1 collections in —

434 li.MNOis Naturai, History Survey Bui.r.iiTiK I'ol. 24, Art. 4 — the vicinity of Quincy, Adams County. In Distribution. Apochthonius moestus is addition, a single individual was present In widely distributed over Illinois; it has been a collection made by Henry Dybas near identified in 65 collections from various Mooseheart, Kane County. The only other parts of the state. The species appears to record available is from Herod, Pope be distributed over most of the United States County, and consists of the questionable east of the Great Plains region. protonymph mentioned above. The species One of the more common pseudoscorpions has a wide distribution in Europe and north- in the eastern and central states, moestus is ern Africa and has been reported from the found very abundantly in the litter and New Ent;land states and Indiana in the debris on the ground in deciduous woods. L'nited States (Chamberlln \929b). It has also been taken from beneath the Ecological data are available only for the bark of decaying logs, in moss, and in mam- collections taken in Adams County. Here mal nests. the species was found chiefly in debris and Illinois Records. —Many specimens, leaf mold in woods, frequently in the vicinity taken throughout the year, are from Alham- of limestone outcroppings along the bluffs bra, Alto Pass, Anna, Bond County, Burks- of the Mississippi River. ville, Cadiz, Charleston, Collinsville, Dan- Illinois Records. Herod: Oct. 12, 19.?,?, ville, Dolson (Clarksville), Eichorn, Foun- ground cover in woods, Frison & Ross, 1 tain Bluf-f, Ganntown, Gef¥, Giant City protonymph. Mooseheart: Sept. 1, 19.S9, State Park, Grafton, Herod, Kellerville,

Henrv Dybas, 1 specimen (cm). Quincv: La Rue (Wolf Lake), Marshall, Monti- Oct. 10, i943; Nov. 1, 1943; July 2, 1944; cello, New Salem State Park, Oakwood, July 29, 1944; Aug. 13, 1944; all by C. C. Pocahontas, Quincy, Sherman, Starved Rock Hoff, many specimens. State Park, Urbana, Vienna, West Vienna, and White Heath. 3. APOCHTHONIUS Chamberlln 4. HETEROCHTHONWS Chamberlin Apochthomus Chamberlln (1929*, p. 66). Genotype, by original designation: Clithov- Hetcrochthonius Chamberlin (1929c, p. 153). ius mocstus Banks. Genotype by original designation: Apoch-

Apochthomus Chamberlin (1929c, p. 152). thonius (Hetcrochthonius) crosbyi Chamber-

Apochthonius Chamberlin. Beier (1932i, p. lin. 41). Hetcrochthonius Chamberlin. Hoff (1945f, p. The genus includes pseudoscorpions with 313). the following characteristics: 22 to 24 setae The members of this genus are similar to

' on the carapace; four eyes; each coxa I members of the genus Apochthonius but with three simple seta-like coxal spines, each differ in having the marginal teeth of the spine originating from a cleft or fissure on chelal fingers with at least the distal teeth the surface of the coxa, fig. 15C; intercoxal well separated and typically composed of tubercle lacking; chelicera with seven setae alternating large and small teeth ; coxa I on the hand; marginal teeth of the chelal with three to six spines; carapace with 20 fingers small, contiguous, and occupying to 24 setae. Only two species are known nearly the full length of the finger margins, in the genus, both from the eastern half of fig. 15B. One species, moestus, occurs in the United States, but only one is recorded eastern North America; two others in the from Illinois. north Pacific Coast region, occidentaUs Key to Species Chamberlin and intermerlius Chamberlin. Body length 1.6-2.0 mm.; length-width ratio Apochthonius moestus (Banks) of palpal femur greater than 4:5, usually

Chthonius morstus Banks (1891, p. 165). greater than 5:0, multispinosus Apochthonius moestus (Banks). Chcmberlin Body length 1.3 mm.; length-width ratio of (1929i, p. 67), Hoff (1944«, p. 125; 1945f, palpal femur 3:8 crosbyi p. 311; 19464, p. 105). This species can be separated easily from Heterochthoniiis multispinosus Hoff other Illinois pseudoscorpions by the three Hetcrochthonius multispinosus Hoff (1945f, coxal spines on each coxa I and by the small p. 314). and contiguous marginal teeth on the chelal This is the only pseudoscorpion thus far fingers. Diagnostic characteristics are illus- found in Illinois that has four to six (in one trated in figs. 11 and 15. specimen, three) spines on each coxa I and ;

June. 1949 Hoff: Pseudoscorpioxs of Illinois 4.^5

'the marginal teeth of the chelal fingers well carapace 0.53 (0.55) mm. long, 0.49 (0.52) spaced and alternately large and small, figs. mm. wide; abdomen 1.45 (1.28) mm. long, 16B, \bC. 0.56 (0.7) mm. wide. Chelicera with finger ' Male.—The present individuals agree 0.285 (0.26) mm. long, serrula exterior with well with the type specimens. A study of 17 (19) plates. Palp with trochanter 0,26 specimens from Duke Forest, the type (0.26) mm. long, 0.145 (0.145) mm. wide; locality, and from Illinois shows that much femur 0.81 (0.79) mm. long, 0.156 (0.15) greater variation occurs than was indicated mm. wide; tibia 0.335 (0.31) mm. long, in the study of the restricted type material. 0.175 (0.16) mm. wide; chela 1.18 (1.15) The following measurements and observa- mm. long, 0.245 (0.245) mm. wide; chelal tions are based on five males from Illinois. hand 0.495 (0.48) mm. long, 0.255 (0.25) Body length 1.65-1.85 mm.; carapace 0.46- mm. deep; chelal finger 0.7 (0.68) mm. 0.51 mm. long, 0.43-0.47 mm. wide; abdo- long. First leg with pars basalis 0.425 men 1.15-1.35 mm. long, 0.65-0.7 mm. wide. (0.405) mm. long, 0.087 (0.078) mm. deep; Chelicera 0.33-0.39 long, 0.19- mm. base pars tibialis 0.2 (0.— ) mm. long, 0.08 (0.08) ,0.24 mm. wide; movable finger 0.2-0.235 mm. deep; tibia 0.255 (0.25) mm. long, ram. long; serrula exterior with 16 to 18 0.061 (0.062) mm. deep; tarsus 0.46 (0.43) ligulate plates. Palp with trochanter 0.21- mm. long, 0.053 (0.051) mm. deep. Fourth 0.215 mm. long, 0.12-0.125 mm. wide: femur leg with pars basalis 0.255 (0,22) mm. deep; 0.65-0.73 mm. long, 0.12-0.13 mm. wide, pars tibialis 0.24 (0.2) mm. deep; entire length 5.4 to 5.65 times the width (ratio of femur I 0.7 (0.67) mm. long; tibia 0.475

; 5.1:1 in type specimens, but ratio in other (0.44) mm. long, 0.105 (0.09) mm. deep; Duke Forest specimens similar to that in metatarsus 0.258 (0.24) mm. long, 0.08

I many individuals from Illinois) ; tibia 0.26- (0.07) mm. deep; telotarsus 0.48 (0.46) 0.29 mm. long, 0.1,^-0.145 mm. wide, length mm. long, 0.053 (0.045) mm. deep; tactile 1.9 to 2.05 times the width; chela 0.93-1.05 seta 0.13 (0.135) mm. from proximal mar- mm. long, 0.185-0.2 mm. wide, length 5.0 gin of tarsus. 'to 5,25 times the width: chelal hand 0,37- Tritonvmph.— Much like the adult but 0.42 mm. long, 0.195-0.205 mm. deep; mov- smaller and segments of the appendages able chelal finger 0.56-0.65 mm. long (a stouter. Body about 1.4 mm. long; carapace little less than in the type specimens) and with both length and width about 0.4 mm. light yellow in color (not reddish-brown as abdomen 1.1 mm. long, about 0.65 mm. wide. given in the original description). First leg Chelicera with movable finger stouter than I with pars basalis 0.36-0,4 mm. long, 0.07- in the adult and with a subterminal nodule 0.075 mm. deep; pars tibialis 0.16-0.195 mm. in which terminate a number of gland ducts; [long, 0.065-0.073 mm. deep; tibia 0.21-0.24 serrula exterior with 16 ligulate plates; imm. long, 0.05-0.057 mm. deep; tarsus 0.4— movable finger 0.18 mm. long, basal setae 0.43 mm. long. 0.045-0.05 mm. deep. Fourth apparently fewer than in the adult. Palpal leg with entire femur 0.57-0.63 mm. long, segments conspicuously stouter than in the pars basalis 0.2-0.23 mm. deep; pars tibialis adult, color a little lighter, setae not so |0.I8-0.215 mm. deep; tibia 0.37-0.425 mm. strongly developed. Palp with trochanter long, 0.08-0.087 mm. deep; metatarsus 0.2- 0.19 mm. long, 0.1 mm. wide; both femora 10.225 mm. long, 0,65-0.70 mm, deep; telo- 0.5 mm. long, one femur 0.115 mm. wide,

I tarsus 0,39-0.45 mm, long, 0.04-0.044 mm, the other 0.12 mm. wide; tibia 0.215 mm. 'deep; tactile seta removed from the proxi- long, about 0.13 mm. wide; chela 0.78 mm. mal margin of the tarsus by 0.12-0.13 mm., long, 0.175 mm. wide; chelal hand 0.29 mm. j being farther removed from the proximal long, 0.17 mm. deep; movable finger 0.51 .margin than indicated for the tvpe material mm. long. Marginal teeth of chelal fingers {(Hoff 1945<-). much as in the adult except fewer in num- Fe.male. In general, the female resem- ber on the fixed finger and with less differ- j — |bles the male except that the body and ap- ence in size between the alternating large pendages are longer and that many of the and small teeth. Movable finger with three i segments of the appendages are stouter. The tactile setae: st not much distad from the

following measurements are of two females, mid-point of the finger, / about two areolar I leach measurement of one followed in paren- diameters distad from st, b removed from

1 theses by the corresponding measurement of the proximal finger margin by less than the other. Bodv length 1.98 (1.85) mm. twice the width of the finger at the level

I — — ;

436 Illinois Natural History Survey Bulletin FoI. 24, Art. 4

of b. Fixed finger with est about midway Illinois Records. Cadiz: Nov. 6, 1942, between isl and the finger tip ; ;/ about three Ross & Sanderson, 2 i , 19. Fountain areolar diameters distad from the level of Bluff: Feb. 22, 1933, Ross & Mohr, 1 im- in the adult except mature. Oct. 12, 1933, Frison & est ; other setae much as Herod: one of the setae on the dorsum of the chelal Ross, 2i (13, ch); Oct. 18, 1944, Ross hand is wanting. The segments of the legs & Sanderson, 1 5 . generally shaped as in the adult except much smaller and stouter; telotarsus of fourth leg Heterochthonius crosbyi (Chamberlin) subfusiform. First leg with pars basalis Apochthonlus (Helerochtlionuis) crosbyi Cham- 0.258 mm. long, 0.066 mm. deep; pars tibialis berlin (1929f, p. 153). 0.133 mm. long, 0.061 mm. deep; tibia 0.145 This species is known only from North mm. long, 0.048 mm. deep; telotarsus 0.285 Carolina, but may eventually be found in mm. long, 0.042 mm. deep. Fourth leg with Illinois. entire femur 0.42 mm. long, 0.158 mm. deep; Recently the writer has been able, through tibia 0.285 mm. long, 0.072 mm. deep; meta- the kindness of Henry Dietrich of the Cor- tarsus 0.152 mm. long, 0.06 mm. deep; telo- nell University Agricultural Experiment tarsus 0.292 mm. long, 0.046 mm. deep; Station, to examine the holotype of Heter- tactile seta removed from the proximal ochthonius crosbyi. A comparison of crosbyi margin of the telotarsus by about 0.075 mm. and multispinosus indicates that crosbyi is much smaller than multispinosus and that

there is no possibility of confusing the two species. The following measurements were secured of the type of crosbyi and serve to supplement descriptive material given in the literature: body length 1.3 mm. (not 1.5 mm. as recorded in the original description,

Chamberlin 1929f) ; each palp with femur 0.5 mm. long and 0.13 mm. wide; chela somewhat damaged but apparently about 0.78 mm. long; movable chelal finger 0.54 mm. long.

5. MUNDOCHTHONIUS Chamberlin

Mundochthonnis Chamberlin (1929A, p. 64). Genotype, by original designation: Mundocli- tlionius erosidens Chamberlin.

Mundochthonius Chamberlin. Beier (1932i, p.

. 36). Members of the genus Mundochthonius may be recognized by the simple chelal teeth eight setae; Fig. 16. Heteroclithonius multispinosus S . each tergite with usually four to A, chela, dorsal view; B, chela, lateral view; intercoxal tubercle with two setae; only C, more distal marginal teeth of chela. coxa II with spines, figs. 17Z), 17£. Previ- ously, the genus was known from a number Distribution.—This species is infrequent of species recorded from the western United in Illinois, having been taken in only four States and from Japan. The two Illinois collections. Two of these collections were species described below constitute the first from Pope County, one from Jackson records of this genus east of the Rockies in County, and one from Hardin County. The North America. only other record is from Duke Forest, Key to Species Durham, North Carolina, the type locality. Palpal femur longer than 0.3 mm.; chela longer The number of specimens found in the Illi- than 0.5 mm.; length of palpal chela (with nois collections is small: four males, two an occasional exception) at least 4.2 times females, and one tritonymph. the width; mesal comb of coxa II irregularly This species has been taken only from fused at base, figs. 17D, ME rossi ground cover, both in Illinois and in North Palpal femur always shorter than 0.3 mm.; Carolina. chela shorter than 0.5 mm.; length of palpal —

June. 1949 Hoff: PsEunoscoRPioNS of Illinois 437

Fig. 17. Miindoi htlionius rossi. A, teeth of distal part of margin of fixed chelal finger, B, of palp, lateral of holotype, i, arrow points proximad ; dorsal view paratype, c? ; C, view

II, /:, of coxa II, allotype, chela, holotype, i ; D, spines of coxa paratype, 9 ; spines 9-

chela always less than 4.2 times the width; the farthest lateral one of each side is mesal comh of coxa II fused symmetrically located a little distance from the actual at base to form a fan-shaped structure, fig. carapacic margin and close to the eye; pos- sandersoni 18D terior margin of carapace with two setae; total setae on carapace 18; carapace smooth Mundochthoiiiiis rossi new species except for netlike markings on the sides and Individuals of this species may be recog- sometimes along the posterior margin; cara- nized by characteristics given in the key and pace narrowed a little toward the anterior

illustrated in figs. MB. \7D. end, sides slightly conve.x ; length of cara- Male.—Unless otherwise indicated, ob- pace 0..^8-0.41 mm.; width a little greater servations and measurements are based on than the length, 0.385-0.415 mm.; ocular

four individuals. Body and palps light yel- width 0.38-0.39 mm. Tergites 1 and 2 each low in color; body and appendages moder- with four setae, tergites 3 through 9 each ately slender; body length 1.05-1.2 mm. with six setae; tergites almost smooth, undi-

Carapace subcjuadrate ; two very weakly de- vided. Medial setae of sternites much longer veloped eyes, each located about its own than lateral setae. Pleural membranes with diameter from the anterior carapacic mar- regular rows of fine punctations. Length of gin; eyes hardly discernible in caustic- abdomen 0.7-0.8 mm., greatest breadth 0.41- treated individuals. Anterior margin of 0.48 mm. carapace medially serrate with a small tri- Chelicera.—A little darker than the cara-

angular, but variable, epistome ; anterior pace ; base with six setae, almost smooth. margin of carapace with six setae, of which Length of chelicera 0.27-0.29 mm., width 438 Illinois Natural History Survey Bulletin Vol. 24. .hi. }4 of base 0.155-0.16 mm. Fixed finger basally fingers subquadrate at the distal end of the stout, terminally narrowed and acute; tip row and each tooth with a small cusp on of apical tooth brown and sclerotic; inner the proximal corner; teeth of the proximal margin of finger with about 10 conical and part of each row acuspid and somewhat acute denticles, usually the distal first and rounded and flattened; teeth, fig. 17^/, regu- third much larger than the others. Movable larly spaced along virtually the entire finger finger moderately stout, gently curved, es- margin; each finger with usually between pecially near the tip; tip of apical tooth 50 and 60 teeth. Tactile setae of chela ar- brown and sclerotic; spinneret represented ranged as indicated in fig. 17C by a rounded and poorly developed knob, Legs.—Measurements and observations apparently without gland ducts; galeal seta based on two males; whenever the two show near the mid-point of the finger; inner mar- a significant difference, the measurement of gin of movable finger with about eight the holotype is followed in parentheses by denticles, much like those of the other finger the corresponding measurement of a male in general appearance; serrula exterior with paratype. Surfaces of segments smooth; 13 to 15 ligulate plates; length of movable setae not abundant except on the distal seg- finger about 0.16 mm. ments; each coxa II with three (occasion- Palp.—Fig. 17B. Moderately stout, chela ally two) to five irregular and usually ser- slender; surface of segments smooth. Meas- rate spines, these fused at their bases. First urements given as the limits of range leg with pars basalis subcylindrical, slightly secured from four mounted individuals. deeper across the distal end than elsewhere, Trochanter with flexor margin flatly con- 0.192 (0.201) mm. long, 0.053 mm. deep; vex in the center and with a few long setae; pars tibialis with weakly convex extensor 1.5-1.7 mm. long, 0.92-0.103 mm. wide; margin, more convex flexor margin, 0.11 length 1.6 to 1.7 times the width. Femur (0.115) mm. long, 0.05 (0.053) mm. deep; subcylindrical, extensor margin weakly con- tibia subcylindrical, 0.118 (0.128) mm. long, vex or nearly straight in middle, more con- 0.038 (0.041) mm. deep; tarsus tapering a vex near the ends; flexor margin slightly little toward the distal end, 0.2 (0.217) convex beyond the mid-point ; setae of the mm. long, 0.034 mm. deep. Fourth leg with flexor surface much longer than those of the pars basalis very stout, 0.145 mm. deep; extensor surface; 0.345-0.365 mm. long, pars tibialis 0.133 (0.137) mm. deep; entire greatest width just distad from the mid- femur 0.327 (0.345) mm. long; tibia with point and equal to 0.085-0.09 mm., length the distal one-half of the flexor margin between 4.0 and 4.15 times the width. Tibia markedly convex, 0.247 (0.258) mm. long, with a few long and slender setae, especially 0.068 (0.071) mm. deep; metatarsus with on the extensor surface ; outer margin con- both margins nearly straight, much less deep vex, inner margin weakly concave' to at the distal than at the proximal end, 0.1 straight; widest across the extreme distal (0.112) mm. long, 0.05 (0.051) mm. deep; end; 0.177-0.2 mm. long (usually greater metatarsus with a conspicuous pseudotactile than 0.19 mm.), 0.105-0.11 ram. wide; seta on the extensor surface not far from length between 1.65 and 1.85 times the the proximal margin; telotarsus subcylindri- width. Chela with hand rather stout and cal, 0.208 (0.205) mm. long, 0.036 (0.035) fingers slightly curved; both margins of mm. deep, a pseudotactile seta placed 0.068 hand evenly convex, but with the flexor (0.07) mm. from the proximal margin. margin in most individuals conspicuously Genital Complex.—Posterior operculum more convex than the extensor ; chela 0.55- with about eight marginal setae; 20 to 25 0.585 mm. long, 0.122-0.132 mm. wide, setae superficially placed on each side of the length 4.4 to 4.5 times the width ; chelal genital opening; about 10 setae on the an- hand 0.203-0.21 mm. long; depth of hand terior operculum. nearly equal to the width; movable finger Female.—Unless otherwise indicated, 0.36-0.385 mm. long. Viewed from the side, observations and measurements are based chelal hand, fig. 17C, with ventral margin on three individuals; measurements given

moderately and evenly convex ; dorsal margin are the limits of range. Like the male in slightly convex, especially in the region of virtually all respects; body length 1.08-1.2 the tactile setae of the dorsum of the hand; mm. ; carapace 0.4—0.43 mm. long, width fixed finger nearly straight, movable finger equal to length ; abdomen 0.4—0.55 mm. wide. slightly curved. Marginal teeth of chelal Clielicera.—Like that of the male except j June, 1949 Hoff: Pseudoscorpions of Illinois 439

the spinneret is better developed, forming a pacic epistome less prominent than in adult; nodule in which gland ducts appear to ter- tergal chaetotaxy much as in the adult; minate; serrula exterior of 14 lifxulatc plates: body 0.86 mm. long; carapace 0.29 mm. length of chelicera 0.27-0.31 mm., width of long, greatest width 0.28 mm., ocular and base 0.16-0.185 mm.; movable finger vari- posterior width 0,26 mm.; abdomen 0.56 able, 0.165-0.195 mm. long. mm. long, about 0.35 mm. wide. Palp.—Much as in the male but segments Chelicera.—Details much as in the adult, possibly a little larger and femur a little but lighter in color, smaller, and stouter; stouter. Trochanter 0.152-0.19 mm. long, about eight setae in the flagellum ; serrula 0.09.5-0.11 mm. wide, length 1.6.? to 1.7.? exterior of 12 to 13 plates; length of cheli- times the width; femur 0..?+-0..?95 mm. cera 0.21 mm.; length of movable finger (allotype 0..?72 mm.) long, 0.091-0.102 mm. 0.133 mm. wide, length i.l to .?.9.? (allotype .?.9.?) times Palp.—Measurements of the single avail- width; tibia 0.18.?-0.22 mm. long. 0.10.?- able tritonymph as follows: trochanter 0.135 0.129 mm. wide, length 1.7 to 1.8 times mm. long, 0.084 mm. wide; femur 0.267 width; chela 0.55-0.635 mm. (allotype 0.58 mm. long, 0.075 mm. wide; tibia 0.152 mm. mm.) long, 0.125-0.155 mm. wide, length long, 0.091 mm. wide; chela 0.43 mm. long, 4.1 to 4.45 (allotype 4.45) times width: 0.103 mm. wide; chelal hand 0.16 mm. long, chelal hand 0.205-6.24 mm. (allotype 0.217 0.103 mm. deep; movable finger 0.29 mm. mm.) long, depth equal to width; movable long. \'iewed laterally, fingers somewhat finger 0.37-0.41 mm. (allotype 0.38 mm.) stouter than in male; dorsal margin of hand long. \'iewed laterally the shape of haml nearly straight; marginal teeth of same gen- and fingers, as well as the dentation and eral nature as in male but slightly fewer in chaetotaxy of fingers, essentially as in the number. Movable finger with three setae, male. difficult to homologize definitely with the

Legs.—As in the male; spines of coxa 11 setae of the adult; one seta, possibly /, extremely variable, figs. 17D, 17£. Some- located slightly distad from the mid-point of times longer than width of base (as in the the finger ; a second seta, possibly st, placed allotype). Measurements given are of two somewhat proximad from the mid-point of individuals, each measurement of the allo- the finger and about three areolar diam- type followed in parentheses by the corre- eters from the first seta; sb probably want- sponding measurement of the female para- ing; b removed from the proximal finger type. First leg: pars basalis 0.205 (0.216) margin by a distance about equal to the mm. long, 0.055 (0.061) mm. deep; pars width of the finger at the level of the seta. tibialis 0.112 (0.129) mm. long, 0.053 Fixed finger with tactile setae much as in (0.061) mm. deep; tibia 0.129 (0.137) mm. the adult except only one seta on the dorsum long, 0.04 (0.044) mm. deep; tarsus 0.21 =i of the hand. (0.23) mm. long, 0.0.?4 (0.036) mm. deep. Leys.—Segments essentially as in the adult Fourth leg: pars basalis 0.14 (0.155) mm. except much smaller and stouter; each coxa deep; pars tibialis 0.13 (0.137) mm. deep; II with four or five apparently simple spines, entire femur 0.354 (0.38) mm. long; tibia unequal in length. First leg: pars basalis 0.263 (0.29) mm. long, 0.069 (0.076) mm. about 0.15 mm. long, 0.049 mm. deep; pars deep; metatarsus 0.114 (0.118) mm. long, tibialis 0.085 mm. long, 0.045 mm. deep; 0.052 (0.061) mm. deep; telotarsus 0.225 tibia 0.095 mm. long, 0.037 mm. deep; telo- (0.235) mm. long, 0.036 (0.04) mm. deep; tarsus 0.148 mm. long, 0.03 mm. deep. tactile seta located 0.076 (0.08) mm. from Fourth leg: pars basalis 0.11 mm. deep; proximal margin of the telotarsus. pars tibialis 0.102 mm. deep; entire femur Genital Cumplex.— Position of mounted 0.258 mm. long; tibia 0.193 mm. long, 0.06 specimens prevents description of the chaeto- mm. deep ; metatarsus 0.08 mm. long, 0.045 taxy of the genital complex. However, one mm. deep; telotarsus 0.159 mm. long, 0.038 female examined in alcohol had 8 to 10 setae mm. deep; seta 0.045 mm. from proximal on the posterior operculum and 10 setae on margin of telotarsus. the anterior operculum. The genital com- Deutonymph.—Observations based on plex is simple and not sclerotized. one mounted individual. Body and append- Tritoxy.mph.—General appearance as ages smaller and stouter than in the trito- in the male but appendages and body nymph; body not treated with caustic, and smaller, stouter, and lighter in color; cara- chaetotaxy of carapace and tergites not ob- —

440 Illinois Natural History Survey Bulletin Fol. 24, Art. 4

Illinois served ; body 0.75 mm. long ; carapace nearly The following are additional 0.24 mm. long, about 0.29 mm. wide, pos- records not included in the paratype series: terior width 0.28 mm., ocular width 0.24 Amboy: Dec. 6, 1945, Ross & Sanderson, mm.; two weakly developed eyes; abdomen 1 specimen. Mount Carroll: Smith Park, about 0.52 mm. long, 0.3 mm. wide. Dec. 6, 1945, 8 specimens. White Pines CheUcera.—Much like that of the trito- Forest State Park: soil cover in oak-hick-

1 nymph ; flagellum with about six setae; ory grove, Oct. 8, 1933, J. Alsterlund, slightly fewer marginal teeth on fingers and specimen. apparently fewer setae on the base; serrula This species occurred in eight collections exterior with 10 plates; movable finger from the northern one-fourth of the state, 0.102 mm. long. all taken from ground cover and debris,

Palp.—Segments fairly stout ; trochanter especially around sandstone outcroppings. with the flexor margin irregularly convex, Many of the collections were from Starved 0.103 mm. long, 0.068 mm. wide; femur Rock State Park and White Pines Forest distinctly subcylindrical in outline, 0.19 mm. State Park, where conditions are favorable long, 0.059 mm. wide; tibia with extensor for the preservation of the original fauna. margin convex, flexor margin weakly concave, 0.12 mm. long, 0.075 mm. wide; chela Mundochthonius sandersoni new species

0.325 mm. long, 0.083 mm. wide ; chelal hand 0.12 mm. long, 0.08 mm. deep; movable This species can be identified by charac- chelal finger 0.215 mm. long. Viewed later- teristics given in the preceding key and illus- ally, fingers appear fairly stout, both a little trated in fig. 18. curved; 30 to 35 teeth on each finger, the M.\LE.—Measurements and ratios repre- teeth of the basal one-third of each finger sent the limits of range of four individuals. distinctly rudimentary. Movable finger with Small, fragile, light yellow in color; body two tactile setae, one (possibly st) located and appendages moderately stout; body just within the basal one-third of the finger length 0.75-0.9 mm. Carapace nearly square and the other (possibly t) located a little in dorsal outline; surface virtually smooth distance proximad from the mid-point of the except marked on the sides by netlike lines; finger. Fixed finger with setae somewhat as posterior margin straight, lateral margins

in the tritonymph except it and est relatively usually a little convex; subtriangular epi- more basal in position, and only two setae stome with a conspicuously serrate margin; (probably esb or eb wanting) in the group four setae along the posterior carapacic near the base of the finger. margin; total setae on the carapace probably Legs.—Segments much smaller and stouter 20 (difficult to determine in specimens ex- entirely than in the tritonymph; spines of each coxa amined) ; eyes vestigial, often want- II variable, both simple and deeply incised ing; length of carapace including the epi- spines present. First leg (measurements stome 0.28-0.31 mm., greatest width about subject to possible error as the leg was not equal to the length, posterior width slightly

dissected from the specimen) : pars basalis less than the greatest width and ranging 0.1 mm. long, 0.036 mm. deep; pars tibialis from 0.27 to 0.31 mm. Abdomen weakly not divided; 0.065 mm. long, 0.036 mm. deep ; tibia 0.068 ovate; tergites and sternites mm. long, 0.034 mm. deep; tarsus about 0.12 tergites 1, 2, and 3 each with four acuminate mm. long, 0.029 mm. deep. Fourth leg not setae, more posterior tergites each with six in a position favorable for measuring. setae; sternites 5 through 11 with 8 to 10 Holotype, male.^—Starved Rock State acuminate setae; setae of sternite 4 not Park, Illinois: May 6, 1944, M. W. Sander- determined in the male; length of abdomen son. 0.5-0.6 mm., width 0.3-0.37 mm. Pleural Allotype, female.—Starved Rock State membranes finely and weakly papillose. Park, Illinois: Nov. 8, 1943, mossy debris CheUcera.—Large in ratio to the rest of on shelves. Ross and Sanderson. the animal; slightly darker in color than the Paratypes. Illinois. — Starved Rock body and legs; 0.19-0.215 mm. long, width 0.115-0.13 base with six State Park : Same data as for holotype, of base mm.; surfaces of base 5$, 19, 1 tritonymph; same data as for acuminate setae; lateral allotype, 2$, 19. White Pines Forest spinose, spines very short and readily seen State Park: July 14, 1944, Frison & San- only in relief; flagellum of about nine slender derson, 2 2,1 deutonymph, 2 tritonymphs. plumose setae. Fixed finger curved, apical —

June, 1949 HoFF: PSEUDOSCORI'IONS OF ILLINOIS 441

Fig. 18. Mundochthonitis sandersoni. A, movable cheliceral finger, serrula omitted, paratype, 2 ; B, fourth leg, paratype, 9 ; C, lateral view of chela, holotype, <5 ; D, coxal spines, paratype, i ; E, dorsal view of palp, paratype, £ ; F, epistome, paratype, 9 ; G, epistoine, paratype, 9, another variation. tooth sclerotized and strong; nearly 12 usually flatly convex in the central portion; acute teeth along the internal finger margin, 0.114-0.12.?" mm. long, 0.064-0.072 mm. the distal tooth very heavy, teeth toward wide, length 1.7 to 1.8 times the width. base weaker; serrula interior reduced; Mov- Femur subcylindrical ; inner margin slightly able finger 0.1-0.13 mm. long; galeal seta concave, outer margin nearly straight in the long, inserted near the mid-point of the central portion but convex at each end, wid- finger; apical tooth strong and sclerotic; est in the distal half; 0.22-0.25 mm. long, galea represented by a prominent knob, 0.064-0.072 mm. wide, length 3.45 to 3.65 which appears to be the terminus for a few times the width. Tibia subtriangular, wid- gland ducts; usually between 8 and 10 acute, est across the extreme distal end; inner conical teeth along the distal one-half or margin weakly concave, outer margin con- two-thirds of the finger margin, with the vex, usually a little flatly convex; 0.125- most distal tooth larger than the others 0.15 mm. long, 0.077-0.084 mm. wide, and located some distance from the next length between 1.63 and 1.73 times the more proximal tooth; serrula exterior of 14 width. Chela with hand moderately stout; to 15 ligulate plates. fingers slender, strongly but evenly curved Palp.— Fig. 18£. Light yellow in color in dorsal view; hand with outer margin with chela very slightly darker than the rest flatly convex, inner margin more convex; of the palp; moderately stout; segments 0.37^.42 mm. long, 0.091-0.102 mm. wide, with a few acuminate setae ; segments length 4.0 to 4.15 times width; hand 0.136- smooth except the dorsum of the chelal hand. 0.152 mm. long, 0.09-0.1 mm. deep; movable Trochanter with irregular flexor margin, finger 0.25-0.285 mm. long, usually 0.27 ;

442 Illinois Natural History Survey Bulletin Fol. 24, Art. 4 mm. or more. Viewed laterally, dorsal and face very numerous, 0.122-0.136 mm. long, ventral margins of the hand weakly convex, 0.027-0.3 mm. deep, length 4.47 to 4.54 tig. 18C, with the arc of the dorsal margin times the depth; seta of extensor surface of broken by the insertion of the two tactile telotarsus removed by 0.03-0.035 mm. from setae, ib and isb, on the dorsum of the hand the proximal margin of the segment. fixed finger in lateral view with straight Genital Complex.—Anterior operculum inner margin, outer margin weakly convex, with 10 to 12 scattered setae; posterior finger tapering rapidly in the distal one- operculum with 12 to 16 marginal setae; fourth; movable finger more slender than 8 to 10 setae on the lateral rim of each side the fixed finger. Both fingers usually with of the aperture; setae small and obscure. from 45 to 55 marginal teeth, varying in Fem.ale.—Unless otherwise indicated, structure from the distal ones, which are measurements are based on seven individu- subquadrate and each with a cusp on the als. Essentially like the male in all details proximal corner, to the proximal ones, which but much larger in actual size of body and are rounded and acuspid ; teeth spaced along appendages, appendages frequently a little most of the finger margin. Tactile setae as stouter. Body length 0.9-1.15 mm.; carapace in fig. ISC. 0.31-0.33 mm. long, 0.29-0.35 mm. wide; Legs.—Moderately stout, light yellow in abdomen usually 0.6-0.8 mm. long and 0.3- color; scattered acuminate setae, numerous 0.45 mm. wide. only on the distal segments. A flat, semi- Chelicera.—As in the male ; length 0.22- lunar blade on each coxa II, fig. 187); the 0.245 mm., width of base 0.13-0.15 mm.; blade irregularly and deeply incised along movable finger, fig. \^A, between 0.135 and the margin and showing considerable inter- 0.15 mm. long; serrula exterior with 14 specific variation; blade wider than long; ligulate plates. two or three minute short spines often Palp.—As in the male. Maxilla usually located medially from the blade. First leg 0.2-0.22 mm. long, about one-half as wide with trochanter 0.064—0.075 mm. long, as long; trochanter 0.125-0.135 mm. long, length 1.23 to 1.33 times the depth; pars 0.068-0.076 mm. wide, length 1.73 to 1.85 basalis subcylindrical, deepest near the dis- times the width ; femur 0.25-0.27 mm. long, tal end, 0.118-0.133 mm. long, 0.04-0.045 0.072-0.08 mm. wide, length 3.4 to 3.5 times mm. deep, length 2.9 to 3.05 times the depth; the width; tibia 0.15-0.156 mm. long, 0.09- pars tibialis stout, 0.065-0.073 mm. long, 0.093 mm. wide, length 1.67 to 1.71 times length between 1.62 and 1.73 times the the width; chela 0.42-0.44 mm. long, 0.11- depth; tibia with extensor margin nearly 0.18 mm. wide, length 3.68 to 3.89 times straight, flexor margin weakly convex, the width; chelal hand 0.158-0.168 mm. 0.076-0.087 mm. long, 0.03-0.034 mm. deep, long, 0.11-0.118 mm. deep, the depth equal length 2.5 to 2.56 times the depth; tarsus to the width; movable finger 0.275-0.295 tapering slightly toward distal end, 0.129- mm. long. 0.145 mm. long, 0.025-0.027 mm. deep, Legs.—As in the male. Measurements length between 4.9 and 5.4 times the depth. based on four individuals. First leg with Fourth leg with femur stout; chaetotaxy trochanter 0.074—0.079 mm. long, length and color much as in the first leg; pars 1.18 to 1.27 times the depth; pars basalis basalis 0.097-0.105 mm. deep; pars tibialis 0.133-0.145 mm. long, 2.95 to 3.05 times the 0.09-0.098 mm. deep; entire femur 0.215- depth; pars tibialis 0.076-0.078 mm. long, 0.24 mm. long, length 2.22 to 2.35 times the length 1.68 to 1.81 times the depth; tibia depth; tibia with the basal one-third of the 0.087-0.095 mm. long, 2.5 to 2.7 times the extensor margin slightly convex, distal two- depth; tarsus 0.132-0.145 mm. long, length thirds of the extensor margin almost 4.35 to 5.4 times the depth, usually under straight, flexor margin weakly S-shaped, 4.6 times the depth. Fourth leg, fig. 18B, greatest depth in the distal one-third; 0.158- with pars basalis 0.1-0.11 mm. deep; pars 0.175 mm. long, 0.05-0.055 mm. deep, length tibialis 0.09-0.1 mm. deep; entire femur 3.15 to 3.3 times the depth; metatarsus stout, 0.24-0.25 mm. long, length 2.15 to 2.3 times a sensory seta near the basal one-fourth of the depth; tibia 0.17-0.18 mm. long, length the extensor margin, 0.061-0.072 mm. long, 3.1 to 3.25 times the depth; metatarsus 0.037-0.041 mm. deep, length 1.6 to 1.95 0.072-0.076 mm. long, 1.65 to 1.75 times times the depth; telotarsus subcylindrical, the depth; telotarsus 0.13-0.14 mm. long, margins nearly straight, setae of flexor sur- length 4.25 to 4.4 times the depth. —

June. 1949 HoFF: PSEUDOSCORPIONS OF ILLINOIS 443

Genital Complex.—Posterior genital oper- ana. Haven's description, although insuffi- culum with seven or eight acuminate setae; cient to permit an accurate generic place- anterior operculum with tour setae on each ment, indicates characters that provide side anteriad and laterad to the genital aper- means for the separation of this unplaced ture and two additional setae just anteriad species from other northeastern species of to the pore. Chthoniini, as given in the key. The types Holotype, male.— Herod, Illinois: April of this species appear to have been lost, 18, 1944. Ross & Sanderson. being neither in the U. S. National Museum Allotj'pe, female.—-Same data as tor nor among the types of Hagen's other species holotype. at the Museum of Comparative Zoology,

Parat>pes.— Illinois.—Same data as for ;uid I have seen no material of the species. it is holotype. 8 i , 59 9. Herod: ground cover Since caves occur in Illinois, possible that this form may be found in the state.

Suborder DIPLOSPHYRONIDA

In North America, and with rare exception elsewhere, members of this suborder may be recognized by the presence of the divided tarsus of each leg.

Key to Superfamilies

Movable finger of chelicera toothed along at least one-fifth of inner margin, fig. 25C Neobisioidea, p. 443 Movable finger of chelicera with either a single tooth or with a small group of teeth at apex of inner margin, fig. 27D Garypoidea, p. 446

Fij5. 19. Microl/isiiim confusum 9. An example of the suborder Diplosphyronida and Superfamily NEOBISIOIDEA the family Neobisiidae. Species belonging to this superfamily have

in woods, Oct. Prison Ross, 1 the movable finger of the chelicera toothed 12, 1933, & S , 3 9. PouNTAiN Bluff: March 18, 1942, on the inner margin; the plates of the serrula interior are not fused; and the sub- Ross & Sanderson, 1 9 . L.'^KE Glend.ale : ground cover, March 17, 1943, Ross & San- terminal setae of the pedal telotarsus are seldom simple. A single family, Neobisiidae, derson, U, 49 ; 1 <5, 19 (ch). La Rue: ground cover, April 19, 1944, Ross & Sander- is present in our immediate fauna but two son, 2 9 (nhs). Thebes: ground cover, other families, Syarinidae and Ideoroncidae, have a very limited number of genera and April 19, 1944, Ross & Sanderson, 5 9 . There are two records in addition to the species in the Rocky Mountain region and

type series. Di.xox Springs: March 7, 1945, in California.

Ross & Sanderson, 1 specimen. VlENN.x: debris in woods. Jan. 25, 1947, B. D. Buries, Kev to Families

5 specimens. 1. Venom apparatus developed in both fixed This species is dedicated to Dr. Milton and movable chelal fingers \V. Sanderson of the Illinois Natural His- Ideoroncidae tory Survey staff. Venom apparatus developed only in the fixed finger, fig. 24 2 2. Pleural membrane of abdomen smoothly UNPLACED SPECIES and longitudinally plicate, never granulate; suture between pars basalis and 6. Genus? packardi Hagen pars tibialis of femur IV at least slightly Blot/inis packardi Hagen (1879, p. 399). oblique to the long axis of the femur, . Chthiinius packardi Banks (1895, p. 13). Syarinidae This species was described from material Pleural membrane ot abdomen granulate collected from caves in Kentucky and Indi- or granulo-striate; suture between parts 444 Illinois Natural History Survey Bulletin Fol. 24, Art. 4

of femur IV truly perpendicular to the but ozarkensis Hoff (1945a) has been delong axis of the femur Neobisiidae scribed from Arkansas, and it is expected that this or related species of Microcreagris IDEORONCIDAE may eventually be found in Illinois.

genus Albiorix Chamberlin is re- The Subfamily NEOBISIINAE ported from the southwestern part of the United States. A key to the species of the This subfamily forms a coherent group

genus is given by Hoff (1945f). of forms in which the galea is either wanting or greatly reduced and represented by SYARINIDAE no more than a sclerotic knob. A single genus is recorded from Illinois. A second

This family is represented in the Ameri- genus, Neobisium Chamberlin, is included

can fauna north of Mexico by one genus, here since it has been reported from Ten- Syarinus Chamberlin, with a limited number nessee. of species in the Rocky Mountain and Pacific Key to Genera Coast areas and by two very restricted genera, Hyarinus Chamberlin and Chitra Four long tactile setae present on movable chelal finger and eight on fixed chelal finger, Chamberlin, in California. fig. 20 8. Neobisium Three long tactile setae present on movable,

NEOBISIIDAE and seven on fixed, chelal finger, fig. 25S. . 9. Microbisiuiti Members of this family are identified by the presence of a venom apparatus only in 8. NEOBISIUM Chamberlin the fixed finger, by the granulate nature of Neobisium Chamberlin (1930, p. 11). Geno the pleural membranes, and by the vertical type, by original designation: Obisium mus suture between the pars basalis and pars coram Leach. tibialis of the third and fourth legs. One The genus, figs. 20, 21, can be recognized subfamily is represented in Illinois, and a by the character given in the key, by the second is known from Arkansas. presence of tactile setae et, est, and it on the distal third rather than the distal fourth or Key to Subfamilies fifth of the fixed chelal finger, and by the Cheliceral galea present, at least almost as no more than moderately slender legs and long as the apical tooth and having one or palp. more branched processes, fig. 23 Ideobisiinae To date this genus has not been reported Cheliceral galea wanting or represented by no from Illinois but is represented by several more than a sclerotic knob, fig. 25C species occurring in the southeastern states. Neobisiinae One of these, tenuis Chamberlin, has been

taken in Tennessee and there is a possibility Subfamily IDEOBISIINAE that it or one of its congeners may ultimately be found in Illinois. While this subfamily has not been reported Chamberlin (1930) described tenuis as a from Illinois, it is possible that, with further variety of carolinensis (Banks 1895). On collecting, members of the genus Microcrea- the basis of differences pointed out by Cham-

ffris may be found in the state. berlin in the original description of tenuis,

it seems probable that this form should have

7. MICROCREAGRIS Balzan specific rather than varietal status. The typical form of carolinensis is found in Microcieatjris Balzan (1891, p. 543). Geno- Georgia and North Carolina, while tenuis type, monobasic: Microcreagris ff'ffas Balzan. is confined to the mountain area of eastern This genus, figs. may be separated 22, 23, Tennessee. Because of its habitat, tenuis is from the other genera of the subfamily by hardly to be expected in our fauna. the way in which the tactile setae t, st, and sb are scattered on the movable ohelal finger 9. MICROBISIUM Chamberlin

rather than clustered submedially. There is Microbisium Chamberlin (1930, pp. 10, 20). a single simple or branched galea. Genotype, by original designation: Obisium This genus is not reported from Illinois, brunneum Hagen. —

Juii,-. 19-1-9 HoFF: PSKUDOSCORPIONS OF ILLINOIS 445

Fig. 20. Neobisium carolinrnsis tenuis 6 Lateral view of chela.

Fig. 21. S'eohisium carolinensis tenuis <5 . Distal part of movable cheliceral finger. 22. Fig. Microireagris ozarkensis i . Dorsal view of palp. Fig. 23. Microcreagris ozarkensis $. Distal half of movable cheliceral finger; g, galea.

Members of this genus are peculiar in been taken in 14 collections from Lake that the number of tactile setae of the chelal County in the northeastern corner of the fingers is reduced to three setae on the mov- state and in 1 collection each from Alexander able finger and seven setae on the fixed and Pulaski counties, both in the extreme finger, hg. 25/?. Males have not been found southern tip of the state. All collections of in this genus. this species from Lake County were made Three species are placed in the genus, two from tamarack bogs. Of the collections eastern ones treated below, and a third, from the southern tip of the state, one was piiri'tdum (Banks), from the southwestern taken from "dry forest" in the Horseshoe states. These are treated by Hoff (1946(). Lake Game Refuge near Olive Branch and the other was from "humus and soil from Key to Species drier part of bank, cypress bottoms" near Palpal femur less than 0.4 mm. long, length Karnak. The distribution seems to indicate between 2.42 and 2.89 times the width confusum that brunneum is associated w'ith acid soil and water and with deciduous coniferous Palpal temur more than 0.4 mm. long, length between 2.87 and 3.2 times the width trees in Illinois associated with either tama- brunneum rack or cypress. Illinois Records.—About 200 adults and Microbisium brunneum (Hagen) nymphs of all sizes from several localities.

: sphagnum in Ohisium brunneum Hagen (1869, p. 52). Antioch moss tamarack bog, Microbisium brunneum (Hagen). Chamberlin Oct. 15, 1942, and Oct. 27, 1943, Ross & (1930, p. 20), Hotf 19+6c, p. 494. Sanderson. K.'\rn.'\k: humus and soil from Mierohisium brunneum (Hagen), in part. drier part of bank, cypress bottoms, Feb. 24, Hotf (1944rt, p. 125; 1946/;, p. 109). 1933, Ross & Mohr. Olive Branch: This species is readily identified by charac- Horseshoe Lake Game Refuge, dry forest, ters indicated in the key. An extensive re- Dec. 2, 1943, Frison & Ayars. Volo: sphag- description of the species is given by Hoff num moss in tamarack bog, Oct. 7, 1933, J. {1946c). Alsterlund; sphagnum moss in tamarack Distribution.—Microbisium brunneum bog, Oct. 27, 1943, Ross & Sanderson. Wau- has a wide geographic range in eastern coND.'i: ground cover in tamarack bog, Canada and in northern United States from March 16, 1933, Frison & Mohr; tamarack New \ ork to Illinois. In Illinois its dis- bog, ground cover, Oct. 20, 1943, Ross & tribution is markedlv discontinuous. It has Sanderson. — ;

446 Illinois Natural History Survey Bulletin Fol. 24, Art. 4

Microbisiutn confusum Hoff are from Adams County, Alhambra, Alto Pass, Antioch, Apple River Canyon State Microbisium brunneum Hoff (non Hagen), in Park, Astoria, Bensenville, Brown- part (1944fl, p. 125; 1946*, p. 109). Mis- Aurora, identification. field Woods, Browning, Burksville, Burton,

Microbisium confusum Hoff (1946c, p. 496). Cadiz, Caledonia, Charleston, Clarksville, CoUinsville, Cook County, Danville, Dixon Identification of this species can be made Springs, Dolson, Elgin, Enfield, fountain by the characteristics given in the Icey and Bluff, Fox Ridge State Park, Freeport, illustrated in figs. 19, 25A, 255. In addition Galena, Geff, Giant City State Park, Graf- to the scheme indicated in the key, the fol- ton, Halfday, Havana, Herod, Highland lowing will help in separating brunneum and Lake (near Grays Lake), Ivanhoe, Kamps- confusum. M. confusum shows the follow- ville, Kell, Kellerville, La Grange, Lake ing average differences when compared with Glendale, Lake Zurich, La Rue, Lincoln, brunneum: the body is smaller; the palp is Logan, Magnolia, Makanda, Marshall, smaller, less sclerotized, less deeply colored, Mascoutah, Mason County, Monticello, and less polished; the palpal femur is con- Mound City, New Windsor, Oakwood, spicuously smaller and stouter; the pedicle Palestine, Palisades State Park, Paloma, of the tibia is commonly less slender and the Palos Park, Peoria, Pocahontas, Quincy, inner margin of the palpal tibia is usually Ruma, Seymour, Sherman, Siloam, (Siloam more evenly rounded or convex ; and the Springs), Starved Rock State Park, Summit, chelal fingers appear stouter when viewed Troy, Urbana, Ursa, Vienna, Volo, Wau- from the dorsum. Additional descriptive conda, Waukegan, White Pines Forest State material is contained in the original descrip- Park, Winthrop Harbor, Zioji. tion (Hoff 1946f). Distribution.—Microbisium confusum Superfamily GARYPOIDEA appears to be the common species of the genus in the Mississippi River valley and Members of this superfamily are charac- the eastern United States. In Illinois it is terized as follows: the movable cheliceral the most widely distributed and most abun- finger, instead of being toothed on the inner dant species of all the pseudoscorpions and margin, bears a simple, or occasionally a has been taken in 148 collections from all subdivided, subterminal lobe ; the plates of parts of the state. It occurs in forest soil the serrula interior are fused basally to form and litter, and in decayed logs or stumps. a velum and only the terminal teeth are free

The species is found associated with brun- the subterminal setae of the telotarsi are neum in the tamarack bogs of northeastern always simple and acute. Three families Illinois. are represented in the United States but Illinois Records.—Many adults and only one, the Garypidae, has representatives nymphs taken during all months of the year in the north-central part of the country.

Fig. 24. Microbisium brunneum 9. A, dorsal view of palp ; \B, lateral view of chela, poison gland (in fixed finger only) shown by dotted line. —

June. 1949 Hoff: Pseudoscorpioxs of Illinois 447

Key to Families

1. Venom apparatus developed in fixed finger only; at base of reduced or vestigial apical tooth of the movable finger is a groove, the receptor venedentis, into which fits the tooth or venedens of the fixed finger Menthiilae Venom apparatus developed in both fixed and movable fingers; movable finger without receptor venedentis - 2. Pleural membrane smoothly and evenly plicate; carapace usually not triangular; coxal area never widened posteriorly; setae of palpal femur and tibia con-

spicuous, always slender and acute . Olpiidae Pleural membrane not smoothly and evenly plicate; carapace definitely triangular TTT-y^ in shape, fig. 27C; coxal area with few exceptions much widened posteriorly; Fig. 25. Microbisium conjusum 2. A, dor- setae of the palpal femur and tibia sal view of palp; B, lateral view of chela; short and inconspicuous; if acute, these C, chelicera, movable finger; g, knoblike galea, setae are very short Garypidae showing silk ducts. A and B same scale as MENTHIDAE fig. 24.

This family is represented in America claws of the pedal tarsi ; the movable chelal north of Mexico by a single genus, Mcntlitis finger has two tactile setae; pars basalis of Chamberlin, a few species of which occur legs I and II is never much longer than the in California. pars tibialis; the femoral articulation of the

first two pairs of legs is only slightly mobile; OLPIIDAE the investing setae of the palps are decidedly lanceolate. Only the following species of The family contains a few genera and this genus is known to occur in North species confined in the United States chiefly America. to the arid and semiarid regions of the South- west. Larca granulata (Banks)

cjranulatus Banks GARYPIDAE Garyfus (1891, p. 163).

This family is characterized by a venom apparatus in each of the chelal fingers; investing setae of palpal femur and tibia short and inconspicuous; pleural membranes granular or with rugose striations, not evenly

striated; carapace subtriangular ; abdomen broader than the cephalothorax. A single genus occurs in central and eastern United States. The only other nearctic genus,

Garypus, is represented by a few species in California and doubtful records from Florida.

10. LARCA Chamberlin

Larca Chamberlin (1930, p. 609). Genotype, Fig. 26. Larca i/ranulala. An example of by original designation: Garypus latiis the suborder Diplosphyronida and the family Hansen. Garypidae. The division of the tarsus into This genus, fig. 26, contains species in metatarsus and telotarsus is so obscure and which the arolia are longer than the terminal weak that it is not discernible in the figure. — — —

448 Illinois Natural History SuR\iiv Bulletin /'//. 24, An. 4

0.185 mm. wide; chela exclusive of pedicle 0.85 mm. long, 0.247 mm. wide; depth of chelal hand 0.215 mm., length 0.44 mm.; movable chelal finger 0.44 mm. long. First leg with pars basalis 0.2.^5 mm. long, 0.09 mm. deep; pars tibialis 0.175 mm. long, 0.103 mm. deep; tibia 0.215 mm. long, 0.075 mm. deep; metatarsus 0.15 mm. long, 0.055 mm. deep; telotarsus 0.14 mm. long, 0.045 mm. deep. Fourth leg with entire femur 0.49 mm. long, 0.133 mm. deep; tibia 0.37 mm. long, 0.088 mm. deep; metatarsus 0.18 mm. long, 0.065 mm. deep; telotarsus 0.175 mm. long, 0.05 mm. deep. In the Illinois collections are several nymphs of two sizes. Since the determination of which nymphal stages are represented

is questionable, it is desirable to wait for descriptions until all three nymphal stages are available for study. Distribution.—This species occurs in the central and northeastern United States. No collections have been taken in Illinois in addition to those previously recorded (HoflE 19464) from Starved Rock State Park (La Salle County) and Fountain Blufif (Jackson County). The species is found chiefly in debris and moss on sandstone ledges. Illinois Records. Fount.ain Bluff: March 18, 1942, Ross & Sanderson, 3 adults. Fig. 27. Lana granulala 9 . A, dorsal Starved Rock St.ate Park: mossy debris view of palp ; B, lateral view of chela ; C, dorsal view of carapace ; D, chelicera, mov- on shelves, sandstone bluff, Nov. 8, 1943, able finger. Ross & Sanderson, 5 adults, 4 nymphs.

Larca ffranulata (Banks). Chamberlin (1930, p. 616), Hoff (19+6/', p. 109). Chernes dentatus Ross (non Banks), (1944, fig. 56). Misidentification.

Individuals of this species are easily recognized by the family characteristics, since this is the only garypid pseudoscorpion in the state. For sight recognition, the following characters are useful: the stout abdomen in which the width is nearly equal to the length, the triangular carapace, and the slender form of the palpal segments, fig. 27^. The following measurements are given for a more detailed check of identifications. They were taken from a female mounted in Canada balsam: body length 2.1 mm.; carapace 0.6 mm. long, 0.8 mm. wide across the posterior margin; abdomen 1.5 mm. long, 1.3 mm. wide; palpal trochanter 0.3 Fig. 28. Psclapliochernes parvus. An ex- mm. long, 0.17 mm. wide; femur 0.66 mm. ample of the suborder Monosphyronida and the long, 0.163 mm. wide; tibia 0.57 mm. long. family Chernetidae. Ju,u. 1949 HoFF: PSEUDOSCORPIONS OF ILLINOIS 44V

Suborder MONOSPHYRONIDA STERNOPHORIDAE

Pseudoscorpions of this suborder have only Representatives of this family are found a single tarsal segment on each leg. Three in western Mexico, southern United States, superfamilies are recorded from America and Australia (Chamberlin 1931(2). Two north of Mexico, only one of which is repre- genera, one of which is of uncertain status, sented in the north-central part of the have been placed in the family. A limited United States. number of species of the genus Simiofilinriis Chamberlin are known from southern and Kev to Si i'Erfamilies southwestern United States and one species

1. With tour prominent eyes. . . Feaelloidea of the genus Garyups Banks has been re-

With two eyes or none, never with tour 2 ported from Florida. The genus Garyops is 2. Kemora ot legs I .ind II similar to those of inadequately described and Sternophortis legs III and IV, with the same type of may eventually prove to be a synonym. articulation Cheiridioidea

Kemora ot legs I and II each with a more or less distinct membranous articulation Superfamily GHELIFEROIDE.\ between pars basalis and pars tibialis, the apex ot the pars basalis often en- Members of this superfamily always have larged, and the less deep base of the the femora of the first and fourth legs pars tibialis frequently appears to fit structurally dissimilar; eyes two or none. int3 it, fig. 44./; femora of legs 111 and The group is represented in America north IV with pars basalis and tibialis more of Mexico by three families, two of which or less fused solidly, about the same have representatives in our area. length where they join, the tusion being a somewhat straight suture, tig. 44S. Cheliferoidea Kev to Families

1. .\t least a few accessory teeth pre.sent on Superfamily FE.\ELLOIDEA chelal lingers, figs. 32D, 34fl, 36./; venom apparatus well developed in The nearctic fauna of this superfamily movable finger only, but may be present contains only the family Pseudogarypidae, as a vestige in the fixed finger represented in North America by a single Cheriietidae, p. 44

Venom apparatus developed only in fixed chela! linger; femoral articulations of legs lacking CHERNETID.AE or vestigial so that the pars tibialis and the pars basalis appear to be fused into one Hoth nearctic subfamilies of this family Cheiridiidae are known from Illinois. In use of the Venom apparatus developed in both chelal following key for their separation, great fingers; femoral articulations of legs well care must be exercised because the tactile

developed . . . Stemophoridae seta of the fourth pedal tarsus is often CHEIRIDIID.\E broken or lost.

Subfamilies This family is represented in America Kev to north of Mexico by a few species of the Setae of body and palps long and acuminate; genus Apocheiridium Chamberlin, found when present, the tactile seta of the fourth only on the west coast of the United States. pedal tarsus is located considerably proximad 450 Illinois Natural History Survey Bulletin Inl. 24, Art. 4

from the mid-point ot the segment Chelanops oblongus (Say). Ewing (1911, p. Lamprochernetinae 79). At least some of the setae of body and palps Lamprochernes oblongus (Say). Beier (1932f, denticulate, well feathered, or plumose, often p. 84). appearing club shaped, figs. 36.^, 37D, 46; Since the type specimens deposited by Say when present, the tactile seta of the fourth in the Philadelphia Academy have apparently pedal tarsus is located near the middle or distad from the middle of the segment been lost, a neotype has been selected and Chernetinae deposited in the collection of the Illinois State Natural History Survey. A detailed Subfamily LAMPROCHERNETINAE description is given here of oblongus because no description is available in the litera-

This subfamily is characterized by a ture except the very brief diagnosis given straight or slightly convex posterior cara- by Beier (1932f). Beier's diagnosis is possi- pacic margin; the setae on the body and bly based on specimens from Pennsylvania palps are long and acuminate ; and, when reported by Ellingsen (1909) as being de- present, the tactile seta of the tarsus of the posited in the Berlin Museum. Illinois fourth leg is inserted near the base of the specimens of this species agree well with tarsus. Only two genera are recorded from Beier's description except that our specimens America north of Mexico. One genus, usually have slightly more slender chelae. Lamprochernes Tomosvary, is found in the This difference was noticed also in speci- eastern and central parts of the United mens from Arkansas and Georgia as previ- States. From California and Florida is re- ously reported (Hoff 1945<7). ported the other genus, Lustrochernes Beier, Ewing (1911) reported material from which contains chiefly species that are of Marshall, Champaign, and Muncie, Illinois, uncertain position because of inadequate de- under the name Chelanops oblongus. His scriptions. material from Marshall, deposited in the Museum of Comparative Zoology, has been re-examined, but his specimens from the 11. LAMPROCHERNES Tomosvary other localities were not available for study. Lamprochernes Tomosvary (1882, p. 185). Male.—The following measurements Genotype by subsequent designation of Beier and ratios are based on three males, includ-

: nodosus Schrank. (1932(-, p. 82) Chelifer ing the neotype. Body slender and elongate; Lamprochernes Tomosvary. Beier (1932f, p. light brown in color with palps a deeper 82). reddish-brown; length of body 1.75-2.1 mm. The genus Larnprochernes is character- Carapace widest near the middle, a little by absence of an accessory tooth on ized the narrower across the posterior margin; 8 or tarsal claws of the legs and by the posi- the 10 setae along the posterior carapacic mar- tion of the tactile setae of the fixed chelal gin; two transverse furrows, the median one finger, it always being clearly farther from deeper than the posterior one ; weak eye the finger tip than ist is from isb. Four spots, hardly discernible in specimens treated nearctic species are known: ellipticus Hoff in caustic; surface of carapace almost (1944i) from Mexico, grossus (Banks) smooth ; length of carapace 0.6-0.65 mm., from Colorado, the and two following. greatest breadth 0.45-0.53 mm., posterior Key to Species breadth 0.45-0.53 mm., ocular width usually about 0.32 mm. Abdomen subcylindri- Hand of chela subquadrate in dorsal view, cal, slender; tergites, except the first two subtruncatc at base, fig. 30.i?; chela exclusive to four and the eleventh, well divided; sur- of pedicle usually less than 0.8 mm. long, length 2.4 to 2.6 times the width, .oblongus face with very weakly developed scalelike Hand of chela subovate, basal margin some- sculpturing; tergal chaetotaxy ranging from what rounded, fig. 29A; chela exclusive of about 10 setae on tergite I to as many as pedicle more than 0.8 mm. long, length 2.8 8 or 10 setae on each tergal half in the to 3.0 times the width minor central and posterior part of the abdomen. Sternites, except XI, weakly divided; usu- Lamprochernes oblongus (Say) ally eight or nine setae in each sternal half

Chelifer oblongus Say (1821, p. 64). but only three or four marginal setae on Chelifer (Lamprochernes) oblongus (Say). each half of sternite IV; sternites with Ellingsen (1909, p. 368). color and sculpturing much as on the ter- —

fune, 1949 Hoff: Pseudoscorpions of Illinois 451

29. Fig. Lamprochernis minor, holotype

Fig. 30. l.amprncliernes ahlongus, neotype <5 . .7, dorsal view of palp; B, lateral view f chela.

itcs; each stigmatie plate with three setae; oi three basal ones are very weakly devel- hdoineii i.2-1.5 mm. long, 0.5-0.7 mm. oped; serrula interior with the four distal I'ide. plates free. Movable finger straight ; sub- Chelicera.—Fig. 8. Yellow in color; fin- apical lobe stout, well developed, and :ers relatively slender; flagellum of three located very close to the base of the apical etae, of which the one farthest anteriad is tooth ; apical tooth with a tendency to form inilaterally serrate along the distal one- two or three poorly developed terminal lalt; hasal and subhasal setae relatively cusps ; galeal seta not reaching to the tip of hort. each with a few very minute, sub- the galea; galea long, slender, usually with erminal denticulations ; hand of chelicera si.\ simple rami in the distal one-half; serrula i ith netlike sculpturing on the anterior or exterior of 17 to 18 ligulate plates; length lorsal aspect; length of chelicera 0.17-0.19 of movable finger 0.145-0.16 mm. nm., width of base 0.1-0.11 mm. Fixed Palp.—Fig. 30/f. Stout, usually deep inger slender; inner aspect of apical tooth reddish-brown in color, occasionally lighter; vith three denticles; inner finger margin setae fairly numerous, long, appearing vith four or five teeth, of which the two acuminate but usually with one to a few 452 Illinois Natlral History Survey Bulletin I'ol. 24, Art. 4 minute, subterminal spinules; surface of seg- S-shaped, 0.23-0.26 mm. long, 0.075-0.085 ments smooth except for minute granules mm. deep, length 3.0 to 3.1 times the depth; on the flexor surface of the femur, on the tarsus subcylindrical in outline, about 0.2 flexor surface and the protuberances of the mm. long, 0.05-0.055 mm. deep. Fourth leg trochanter, on the flexor surface of the tibia, with both margins of the femur evenly and

;in(i usually on the inner surface of the weakly convex, 0.41-0.47 mm. long, 0.145- chelal hand near the finger base. Maxilla 0.167 mm. deep, length 2.7 to 2.8 times the with ventral face subtriangular in outline; depth; tibia 0.31-0.355 mm. long, length 3.3 length about 0..^ mm. Trochanter with both times the depth; tarsus subcylindrical, 0.23- sublateral and subdorsal protuberances little 0.27 mm. long, 0.06-0.068 mm. deep, length elevated; length of trochanter 0.27-0.31 3.7 to 4.0 times the depth; tactile seta of the mm., 1.8 to 1.9 times the width in strict tarsus removed from proximal margin by dorsal view. Femur with pedicle a little 0.06-0.08 mm. wider than long, well separated from the Genital Complex.—Posterior operculum rest of the segment; flexor margin S-shaped, with 8 to 10 setae arranged chiefly in a row extensor margin flatly convex in the central along the margin and with 4 to 6 setae on portion; length measured along the extensor the posterior rim of the aperture. Anterior margin 0.41-0.45 mm., 2.0 to 2.1 times the operculum with 18 to 24 scattered setae. maximum width; over-all or greatest length Female.—Measurements and ratios based 0.45-0.48 mm., 2.2 to 2.3 times the width; on three individuals. Almost identical in width between 0.195 and 0.215 mm. Tibia detail with the male; body length 2.35-2.5 with a pedicle about as long as wide ; tibia mm.; carapace 0.62-0.68 mm. long, 0.49-0.53 much swollen and globose beyond the pedi- mm. wide; abdomen 1.7-1.85 mm. long,

cle ; length 0.415-0.465 mm., width 0.21- 0.75-0.9 mm. wide. 0.24 mm., length 1.9 to 2.0 times the width. Chelicera.—No sexual dimorphism ex- Chela viewed from dorsum with hand heavy hibited; length of chelicera 0.185-0.2 mm., and somewhat subquadrate; fingers stout base 0.105-0.115 mm. wide; movable finger and a little curved; hand basally subtrun- 0.155-0.17 mm. long. cate ; length of chela without pedicle 0.69- Palp.—In general as in male; trochanter 0.77 mm., width 0.27-0.315 mm., length 2.4 0.3-0.31 mm. long, about 0.17 mm. wide;

to 2.6 times the width ; chelal hand without femur with extensor margin 0.43-0.45 mm. the pedicle 0.4—0.43 mm. long, depth usually long, greatest length 0.475-0.5 mm., width less than the width and between 0.24 and 0.2-0.22 mm.; tibia 0.45-0.48 mm. long, 0.31 mm.; movable chelal finger 0.3-0.36 0.23-0.24 mm. wide; chela without pedicle

mm. long. Viewed laterally, fig. 30B, chelal 0.75-0.8 mm. long, 0.3-0.305 mm. wide; hand subquadrate, dorsal and ventral mar- chelal hand without pedicle 0.42-0.44 mm. gins weakly convex, basal margin well long, 0.25-0.28 mm. deep; movable finger rounded and not subtruncate; fingers stout; 0.35-0.38 mm. long. the fixed finger nearly straight, the movable Legs.—As in the male. First leg with en- finger slightly curved; movable finger con- tire femur 0.33-0.355 mm. long, 0.12 mm. spicuously shorter than the hand without deep across the pars tibialis; tibia 0.25-0.26

the pedicle. Marginal teeth of fingers cus- mm. long, 0.08-0.085 mm. deep ; tarsus pid, conical, and contiguous; usually 25 to 0.205-0.235 mm. long, 0.055-0.057 mm. deep. 30 teeth on each finger; in most specimens, Fourth leg with entire femur 0.45-0.48 mm. from 2 to 4 (rarely only 1) accessory teeth long, depth across the pars tibialis 0.165- in each row, with the greater number in 0.168 mm.; tibia 0.335-0.355 mm. long, 0.1- the external row of each finger. Tactile 0.105 mm. deep; tarsus 0.24-0.275 mm. long, setae arranged as in fig. 30B. 0.065-0.072 mm. deep; tactile seta of tarsus Leys.—Yellow in color, often with an between 0.055 and 0.075 mm. from the prox- orange tinge; segments stout; surface often imal margin. marked by netlike or scalelike markings. Genital Complex.—Usually 8 to 10 setae First leg with trochanter 0.1-0.12 mm. long, in a marginal row along the posterior oper- length 1.1 to 1.25 times the depth; pars culum; anterior operculum with 6 to 8 setae basalis 0.1-0.11 mm. deep; pars tibialis posteriad to a compact median group of 10 0.105-0.125 mm. deep, both margins evenly to 14 setae. convex; entire femur 0.3-0.35 mm. long, Neotype, male.—Havana, Illinois, duff 2.7 to 2.9 times the depth; tibia weakly in forest, Nov. 9, 1943, Ross & Sanderson. —

IV49 Hoff: Pseudoscorpions of Illinois 453

Distribution.—This species is uide- 10 setae along the posterior carapacic mar- )read east of the Plains Great area. In all, gin ; carapace moderately granular except on + collections of obluiujiis have been identi- the dorsal surface anteriad to the posterior ed from scattered localities over Illinois. carapacic furrow; length of carapace 0.71 .Imost invariably, this species is taken from mm., greatest width 0.51 mm., width across ndcr the bark of oak logs and stumps, as the posterior margin 0.48 mm. Tergites, idicated both by Ewing's collections and except I, II, and XI, completely divided; y the present series. Rarely the species is surface with scalelike markings; first tergite iken from woody debris and even more with 18 setae, second tergite with 18 to 20 arely from ground cover. setae, about 12 setae on each half-tergite of Illinois Records. Astoria: the under oak central portion of the abdomen ; all setae ark, Nov. 1, 194.^, Ross & Sanderson, 69, acuminate. Sternites divided; sculpturing as $, 2 nymphs. Aurora: Sept. 4, 19.^9, H. on the tergites; each fourth sternal half )ybas. 19 (jc). Bknton: May 31, 1945, with 11 to 12 setae excluding those associ- r. Whitlow, 7 specimens. Elsah: May, ated with the stigmata; each sternal half of

946, C. L. Remington, 2

:ream, Jan. 4, 1943, C. C. Hoflf, 1 nymph; 0.17 mm., width of base about 0.115 mm., 3uth of St. Anthony's Church, under bark length of movable chelal Hnger 0.165 mm. f old snag in pasture, July 8, 1944, C. C. Palp.—Fig. 29^^. Brownish-orange to loff, 1 nymph, 19 (ch). Siloam : Siloam golden in color; setae numerous and acu- prings, under bark of log, Oct. 8, 1945, minate to subacuminate, frequently with a '. C. Hof^', 19 (ch). Urbana: Dodson's few subterminal and terminal spinules; seg-

Voods, under bark of fallen white oak, ments stout to very stout ; the sides of the une 6, 1927, Miller, 19 (jc). Zeigler: maxilla, the entire trochanter, and the inner

)ct. 11, 1933, Prison & Ross, 1 $ . or flexor surfaces of the femur, tibia, and chela moderately granulate; also weakly Lamprochernes minor new species granulate on the extensor surface of the

This species, figs. 29A, 29B, is readily chelal hand near the finger base. Maxilla :parated from oblongus by the shape of 0.345 mm. long, about 0.21 mm. wide. Tro- le palpal chela. In many respects, this new chanter with well-developed subdorsal and pecies shows much closer alTinity to Euro- sublateral protuberances, the former an- ean and North African species than it does terior to the latter; pedicle about as long

D oblotigiis. The closest relationship appears as wide ; trochanter 0.32 mm. long, about

) be with n'jilosus (Schrank) and chyzeri 0.2 mm. wide. Femur very stout; inner

^omosvary. From these two forms, minor margin distinctly S-shaped ; extensor margin lay be separated by the more granular cara- markedly convex; pedicle about as long as ace and differences in the shape of the pal- wide, a distinct notch near the distal end al femur. of the flexor margin; length measured along Male.—Description based on the male the extensor margin (but not following the olotype. Body slender, legs moderately curvatures) 0.52 mm., greatest length 0.56 tout, palps stout; body and legs light brown mm., width 0.24 mm. Tibia club shaped,

1 color, the palps deeper brown; length of swollen beyond the pedicle, which is much ody 2.18 mm. Carapace rounded anteriorly, longer than wide; inner margin evenly con- ides somewhat convex, widest near the vex beyond the pedicle; extensor margin enter; two well-marked, transverse fur- flattened at least in the basal one-half and ows, the posterior one very little closer to convex beyond ; 0.545 mm. long, 0.248 mm.

\\e posterior carapacic margin than to the wide. Chela with the hand suboval in out- little curved and fairly stout; ledian furrow ; no eye spots observed ; about line, fingers a 454 Illinois Natural History Survey Bulletin Fol. 24, Art. 4 flexor margin of ohelal hand moderately long, base between 0.115 and 0.135 mm. convex and extending without interruption wide; movable finger 0.16-0.18 mm. long; into the basal margin ; extensor margin less serrula exterior with 16 to 18 ligulate plates. but not flatly convex pedicle about Palp.— 0.32-0.35 long, 0.22- convex ; Maxilla mm. as long as wide; chela, without pedicle, 0.85 0.24 mm. wide. Trochanter 0.31-0.355 mm. mm. long, 0.29 mm. wide ; chelal hand, with- long, 0.19-0.22 mm. wide, length about 1.6 out pedicle, 0.45 mm. long, 0.275 mm. deep; times the width. Femur 0.48-0.56 mm. in movable finger 0.43 long. As viewed from length along the extensor margin, 0.22-0.255 side, chelal hand, fig. 29B, subovate; fixed fin- mm. wide, length along the extensor margin ger straight, movable finger curved; fingers about 2.2 times the width; greatest length gaping when closed; marginal teeth con- 0.54-0.6 mm., 2.35 to 2.45 times the width. tiguous, cuspid, about 35 on each finger; Tibia 0.515-0.585 mm. long, 0.225-0.27 fixed finger with three external and two mm. wide, length 2.15 to 2.3 times the internal accessory teeth; movable finger with width. Chela without pedicle 0.84-0.93 five external and one internal accessory mm. long, 0.28-0.335 mm. wide, length teeth; nodus ramosus of movable finger 2.78 to 2.97 times the width; chelal hand about two areolar diameters proximad from exclusive of pedicle 0.445-0.51 mm. long, tactile seta t. Tactile setae placed as shown depth a little less than the width; movable in the figure. finger 0.435-0.48 mm. long. Chelal fingers Leffs.—First and second legs weakly with usually 30 to 35 marginal teeth; 4 to 5 granulate, granules merging into scalelike teeth in the external row of accessory teeth sculpturing on the third and fourth legs; on each finger and 1 or 2 in the internal setae acuminate, fairly numerous. First leg row on each finger. Tactile setae located with pars basalis 0.113 mm. deep; pars essentially as in the male. tibialis with both margins moderately con- Legs.—Segments of first leg measifre as vex, 0.113 mm. deep; entire femur 0.35 mm. follows: pars basalis 0.11-0.135 mm. deep; long; tibia very weakly S-shaped, 0.262 mm. pars tibialis 0.107-0.13 mm. deep; entire long, 0.076 mm. deep ; tarsus subcylindrical, femur 0.35-0.385 mm. long, 2.85 to 3.18 0.225 mm. long, 0.053 mm. deep. Fourth times the depth; tibia 0.255-0.285 mm. long, leg with extensor margin of femur evenly 0.074-0.087 mm. deep, length 3.28 to 3.47 convex, flexor margin nearly straight; pars times the depth; tarsus 0.22-0.24 mm. long, J basalis 0.132 mm. deep, pars tibialis 0.165 0.053-0.059 mm. deep, length 4.08-4.22 I mm. deep; entire femur 0.49 mm. long; times the depth. Fourth leg: pars basalis tibia with flexor margin weakly convex, ex- 0.13-0.152 mm. deep; pars tibialis 0.152- tensor margin nearly straight except at the 0.177 mm. deep; entire femur 0.49-0.56 mm. base, a tactile seta on the extensor margin long, length 3.12 to 3.22 times the depth; very near the distal end, tibia 0.38 mm. long, tibia 0.373-0.405 mm. long, 0.1-0.113 mm. 0.102 mm. deep; tarsus subcylindrical, 0.274 deep, length 3.58 to 3.85 times the depth; mm. long, 0.07 mm. deep; tactile seta of tarsus 0.277-0.3 mm. long, 0.068-0.07 mm. tarsus located 0.1 mm. from the proximal deep, length 3.95 to 4.07 times the depth; margin. tactile seta of tarsus located 0.085-0.1 mm. Genital Complex.—Anterior operculum from the proximal margin. with 30 scattered setae; posterior opercu- Genital Complex.—Anterior operculum lum with 18 to 20 setae arranged chiefly in with 22 to 24 (in one individual, only 17) a marginal row and with two pairs of setae setae; posterior operculum with a row of on the posterior rim of the aperture. 10 setae. Female.—Measurements and ratios based Holotype, male.^—-Urbana, Illinois, on three individuals, including the allotype. March 27, 1938, H. H. Ross. Like the male except as noted below. Each Allotype, female.—Same data as for fourth sternal half usually with four setae. holotype. All tergites except the eleventh frequently Paratypes.—Illinois.—Urbana: Same divided. Body 2.0-2.5 mm. long: carapace data as for holotype, 2 5 . Rochester, Sanga- 0.65-0.73 mm. long, 0.55-0.6 mm. wide; mon County, Oct. 3, 1943, H. R. Lowen- posterior width between 0.5 and 0.6 mm.; stam, 1 9 (im). abdomen 1.3-1.85 mm. long, width equal to The Urbana collection was from a rotten about one-half the length. log ; the Rochester collection, from the Chelicera.—Between 0.18 and 0.19 mm. underside of a stone slab in a yard. 1

June, 1949 Hoff: Pseudoscorpions of Illinois 455

Subfamily GHERNETINAE size. If it is, there is sometimes confusion over whether or not a true tactile seta is This subfamily constitutes the most con- present. A true tactile seta varies from an spicuous and important group in our fauna. ordinary seta of the vestiture by having A member of the subfamily may be recog- greater length, by being entirely acuminate, nized by the straight or evenly convex pos- and by being directed at more of a right terior margin of the carapace; by the many angle to the surface of the segment, fig. 31. short and either toothed or more or less club-shaped setae of the palps and dorsum Key to Genera as long of the body ; and by the tactile seta of the 1. Chelicera! galea about two-thirds as the movable chelicera! finger 23. Genus? corticis Chelicera! galea much less than two- thirds as long as the movable finger of the chelicera 2 2. Internal surface of chelal hand with a large, projecting, anvil-shaped structure, fig. 45C. Males of 21. Mirochernes Internal surface ot chelal hand without such projection 3

3. .All interior setae of fixed chelal finger grouped in the basal portion of the finger, fig. 32£ 12. Parachernes At least il situated beyond middle of fixed finger 4 4. Palp slender, palpal femur about four times as long as wide 17. Pseudozaona Palp less slender, moderate to very stout 5 5. Setae of palp leaflike and bilaterally feathered 22. Illinichernes Setae of palp otherwise 6 Fig. 31.—Tarsus of fourth leg showing tac- 6. Tactile seta si of movable chelal finger to sh than to / tile seta, /. A, Paracherncs squarrosus $ ; B, closer

Pselaphnchernes parvus 9 . 15. Dendrochernes Tactile seta st midway between sb and / or nearer the latter 7 fourth tarsus being located near the middle, 7. Tactile seta /.;/ of fixed chelal finger on or distad from the middle, of the segment. the same level as esl or a little proximad The present scheme of classification with- to esl 8 in the subfamily is entirely unstable and Tactile seta isl distad from esl 9 unsatisfactory. In order to circumvent con- 8. Cheliceral flagellum composed of four fourth pedal fused concepts of some older genera, the setae; no tactile seta on in our form, the palpal femur writer has established several new ones even tarsus; and tibia each have a length greater though there is a possibility that one or more than 0.75 mm 13. Chelanops of these may later lapse into synonymy. A Flagellum composed of three setae; a comprehensive revision of the entire sub- tactile seta present on fourth pedal tar- family is needed. sus; length of femur and of tibia less In the following key to genera, two points than 0.6 mm may give the student considerable trouble. 14. Pselaphochernes The setae on the flagellum of chelicera, 9. Setae b and sb of cheliceral hand thick- ened and denticulate mentioned in couplet 8, are often difficult to 19. Uesperochernes distinguish, and therefore observations Not as above, at least seta b acuminate. . should be made of several specimens where- 10 ever possible. Great care must be taken 10. Both seta b and seta sb of cheliceral hand with respect to identification of the tactile acuminate 20. Acuminochernes seta of the fourth pedal tarsus mentioned in Seta b of cheliceral hand acuminate, sb couplet 12, since the s^ta is easily broken denticulate 1 and lost. Also, the seta may be of reduced 11. Palp with following combination of 456 Illinois Natural History Survey Bulletin Jnl. 24. An. 4

characters: length-width ratio of palpal the serrula exterior, and the slightly differ- femur about 2.3;1; length of chela ex- ent size and length-width ratio of the palpal clusive of the pedicle divided by length femur. of femur usually between 1.7 and 1.8; Among the local fauna, sguarrosus can be chela greater than 1.0 mm.; length of identified readily on the basis of the lightly length of femur more than 0.6 mm.; colored silver blotches along the posterior tactile seta present on tarsus of fourth margin of the carapace. No other Illinois leg. Females of 21. Mirochernes pseudoscorpion has such a pigment pattern. Some other combination of palpal characters; tactile seta absent from or Two specimens from Ewing's collections present on tarsus of fourth leg 12 were found to belong to this species. One 12. No tactile seta on tarsus of fourth leg; specimen, a female, deposited in the Museum combination of length-width ratio of of Comparative Zoology, had been labeled chela 2.6-2.75:1 femur 2.3-2.5:1 and of Chelanops virginica but this name had been 16. Reginachernes deleted and the identification C. pallidus Tactile seta present on tarsus of fourth supplied. This specimen was apparently re- leg; Illinois species having a similar ported by Ewing (1911) under the name length-width ratio of both femur and chela (exclusive of pedicle) of palp, pallidus from "under bark" at Areola, Illi- either both greater than 2.6, or both less nois. The date of collection of this speci- than 2.5 18. Dinocheirus men was June 12, 1908. The second specimen available from the Ewing collections

12. PARACHERNES Chamberlin is a male deposited at the Cornell Univer- slide of this specimen Parachernes Chamberlin (1931i, p. 192). sity Museum. The Genotype, by original designation: Para- bears the deleted name Chelanops pallidus, chernes ronnaii Chamberlin. which was replaced by the identification Parachernes Chamberlin. Beier (1932f, p. Chelanops sanborni. The specimen was 116). taken under the bark of a living oak tree Members of this genus can be recognized at Marshall, Illinois, on October 10, 1908. by the grouped condition on the fixed chelal Since Ewing (1911) reported pallidus but finger of the tactile setae it, ist, isb, and ib, not sanborni from Marshall, this specimen

with it clearly farther from the finger tip was probably reported as pallidus. than from isb, fig. 32E; flagellum of three The erroneous identification of the pres- setae; eye spots mostly present; tergites ent species as pallidus (Banks) is easily ex- divided; setae of body and palp toothed or plained since, during the time Ewing worked,

feathered, seldom lightly clavate ; tactile generic and specific characters were poorly seta St of movable chelal finger only a little understood and inadequately described. We

nearer to sb than to / or standing in the now know that the species pallidus belongs

middle between the two, fig. 32£ ; tactile to the genus Dinocheirus as indicated else- seta of the fourth pedal tarsus located distad where in this paper. Cleared specimens of from the mid-point of the segment. A single Dinocheirus pallidus and Parachernes sguar- species is known from the north-central rosus are superficially similar and can easily states. be confused. However, the oheliceral flagellum of pallidus has four setae while there species Parachernes sguarrosus new are only three setae in the cheliceral flagel- Chelanups pallidus Ewing (1911, p. 78), (non lum of sguarrosus. Cherries pallidus Banks). Misidentification. Male.—Measurements and ratios are The present species figs. 32^-32£, bears given as the limits of variation of three indi- considerable relationship to two species de- viduals, including the holotype. Body and scribed by Nathan Banks, Parachernes pul- palps fairly stout, legs moderately slender; chellus from Texas and virginicus from Vir- body and appendages for the most part dis- ginia. From piilchellus, sqiiarrrjsus may be tinctly granular; color varying from yellow distinguished by the absence of silver blotches on the legs to reddish or golden brown to on the outer ends of the abdominal tergites brown on the palps and carapace, and dark and by the flatly convex rather than evenly brown on the tergites; body 1.8-1.9 mm. convex outer margin of the palpal femur. long. Carapace, fig. 32^, with surface coarse- From virginicus, this new species can be ly granular except for a transversely placed distinguished by the more granular nature white blotch along the posterior margin on of the palpal segments, the fewer plates in each side of the median line; posterior mar- ;

r,im', 1949 Hoff: Pseudoscorpions of Illinois 457

;in with 8 to 12 subchivate to clavate mar- of the carapace ; the medial end of some of :inal setae placed just anteriad to the white the tergitcs lighter in color than the rest

)lotches; anterior margin weakly convex, of the tergite ; the lateral ends of tergites vith four stout setae, each with a tew sub- not bearing lightly colored blotches; each erniinal and terminal denticulations ; cara- tergite with a single row of marginal setae jace narrowed rapidly anteriad to the mid- and, in addition, frequently with a lateral )oint, posterior portions of lateral margins seta at each outer end of the tergite; setae

)f two sides nearly parallel; the median of all but the eleventh tergite weakly cla-

:ransverse furrow near the mid-point of the vate ; four to seven setae on each half-ter-

(ace of the carapace, the posterior furrow gite ; eleventh tergite with four to five pairs mteriad to the white blotch of each side of subacuminate to acuminate setae. Ster- ind a little closer to the posterior carapacic nites 4 through 10 divided; sternites dark Tiargin than to the median furrow; setae brown, surface marked by scalelike or nct-

)f face and sides of carapace short, slender, iike impressions; setae acuminate, moder- iubclavate or paucidenticulate ; a single pair ately long, very slender; fourth sternite jf eye spots; carapace 0.65-0.7 mm. long, with eight setae; each of sternites 5 through Lvidth just posteriad to the center of the 10 with 12 to 18 setae; sternite 11 with ;arapace 0.5-0.6 mm.; ocular width about three pairs of setae, the medial and lateral

D.3 mm. Abdomen suboval in general shape pairs of which are very long. Pleural mem- 1.1-1.3 mm. long; 0.8-0.9 mm. wide. Ter- branes with wavy parallel striations; an-

;ites except the eleventh divided ; dark brown terior stigmatic plate with one or two in color; granulations very similar to those acuminate setae, posterior plate with one.

M-W-4

Fi^. ll.—Parachernes squarrmus. .1, dorsal view of carapace and five anterior tergites,

(.', tip of movable cheliceral finger, holotype i ; B, dorsal view of palp, holoiype i ; galea and tritonyniph with teeth enlarged, paralype ; paratype i ; /J, lateral view of movable chelal finger f, lateral view of chela, allotype 9. 458 Illinois Natural History Survey Bulletin Fol. 24. Art. 4

Chelicera.—Light brown in color, some- Tibia pedicellate, with pedicle about as long times with a greenish tinge; 0.185-0.19 mm. as wide; outer margin of tibia including the long, base about 0.12 mm. wide; movable pedicle evenly convex ; inner margin centrally finger 0.16-0.17 mm. long. Flagellum of bulged and convex but slightly flattened in three setae, the longest having six to eight the distal one-third ; setae much as in the fine denticulations along the distal half of femur; flexor or medial surface coarsely the anterior margin. Fixed finger with con- granulate; outer or lateral surface virtually spicuous lamina exterior ; most teeth of the smooth; 0.45-0.48 mm. long, 0.215-0.235 serrula interior fused, but the distal four mm. wide, length 2.0 to 2.15 times the teeth free and with serrate margins; inner width. Chela stout; setae of hand relatively margin of finger with three retroconical long, with one or two very fine submedial teeth near the distal end ; apical tooth acute to subterminal denticulations on each; setae and with three small, rounded denticles on of fingers acuminate; hand with a few fine the inner surface. Movable finger, fig. 32C, granulations on the inner aspect near the fairly stout, slightly curved ; apical tooth base of the fingers, otherwise smooth; flexor well developed, terminally split to form two margin of chelal hand slightly more convex cusps; subapical tooth weakly developed, than the extensor; pedicle placed nearer the located just distad from the insertion of the outer than the inner surface of the hand; galeal seta; two small, conical denticles or fingers evenly curved; chela, without pedicle, accessory teeth sometimes found on the inner 0.785-0.835 mm. long, 0.32-0.33 mm. wide, margin of the movable finger between the length 2.4 to 2.5 times the width; chelal subapical tooth and the base of the apical hand 0.32-0.36 mm. deep, hand, without tooth; galeal seta extending slightly beyond pedicle, 0.41-0.43 mm. long; movable finger the tip of the galea; serrula exterior of 19 about equal in length to length of hand with- to 21 ligulate plates; galea fairly stout and out pedicle. As viewed from the side, dorsal straight, with six or seven simple rami margin of the chelal hand more convex than confined to the terminal one-half or one- the ventral; the pedicle displaced toward third of the galea; considerable variation the ventral side; fixed finger stout and nearly in the stoutness of the galea. straight; movable finger distinctly curved. Palp.—Fig. 32B. Lateral surface of max- Marginal teeth of both fingers contiguous; illa, all surfaces of trochanter, and the flexor distal teeth acute and each with a well- surfaces of the femur and tibia coarsely marked cusp, proximal teeth more rounded granulate; rest of palp weakly granular to and with weak cusps; 30 to 35 marginal smooth; setae varying from acuminate to teeth on each finger; each finger with five subclavate and paucidenticulate. Maxilla to seven external and two or three internal with acuminate and slender setae; 0.295- accessory teeth. Tactile setae as in fig. 32B; 0.305 mm. long, 0.22-0.23 mm. wide, length nodus ramosus of movable finger located 1.35 to 1.4 times the width. Trochanter slightly proximad from the areole of tactile with inner margin regularly convex, surface seta t. bearing numerous short setae with terminal Legs.—Surfaces, except the posterior, of

and subterminal denticulations ; a well- the basal segments of legs fairly well marked rounded, dorsolateral protuberance present; by scalelike sculpturing, becoming weaker on trochanter 0.24-0.26 mm. long, 0.17-0.175 the distal segments; setae variable. First mm. wide. Femur with pedicle wider than leg with stout trochanter, 0.11-0.115 mm. long, well separated from the rest of the long; pars basalis 0.115-0.12 mm. deep; pars segment; extensor margin flatly convex, ex- tibialis almost smooth to coarsely granulate, cept at the ends; flexor margin distinctly 0.107-0.122 mm. deep; entire femur 0.3-0.35 S-shaped, concave in the distal half of the mm. long; tibia with extensor margin segment but distinctly convex in the proxi- weakly S-shaped, greatest depth in the distal mal portion; granulations coarser and much one-fourth, 0.23-0.25 mm. long, 0.072-0.087 more marked on the medial than on the mm. deep, length 2.85 to 3.2 times the depth; sometimes nearly smooth, outer surface; tarsus subcylindrical, with weak sculpturing, setae of the medial surface sparse and sub- setae not abundant, 0.23-0.24 mm. long, clavate, setae of the lateral surface some- 0.053-0.057 mm. deep, length 4.2 to 4.4 what longer and with few denticulations; times the depth. Fourth leg with pars ba- femur 0.48-0.505 mm. long, 0.19-0.22 mm. salis almost smooth, a few long acuminate wide, length 2.3 to 2.5 times the width. setae on the flexor surface, subtriangular in ;; ;

ne. 1949 Hoff: Pseudoscorpions of Illinois 459

tline, 0.137-0.14 mm. deep; pars tibialis as in the male except slightly more variation th anterior surface conspicuously sculp- in number. Tactile setae arranged as in red, posterior surface almost smooth, the male. xor margin almost straight, 0.165-0.175 Legs.—Essentially as in the opposite sex n. deep; entire femur 0.44—0.465 mm. some segments, however, slightly larger in ig, length 2.65 to 2.75 times the depth actual size and sometimes a little more ia with extensor margin slightly S-shaped extensively granulate. First leg with tro- almost straight, 0.35-0.37 mm. long, chanter 0.115-0.125 mm. long; pars basalis (95-0.102 mm. deep, length 3.65 to 3.85 0.12.5-0.133 mm. deep; pars tibialis 0.12- nes the depth; tarsus subcylindrical, nu- 0.13 mm. deep; entire femur 0.33-0.375 mm. rrous acute setae on the flexor surface, a long; tibia 0.24-0.26 mm. long, 0.08-0.085

,v relatively long and subterminally den- mm. deep, length 2.8 to 3.05 times the depth; ulate setae on the extensor surface, weak- tarsus 0.235-0.255 mm. long. 0.06-0.065 developed sculpturing. 0.28-0.30 mm. mm. deep, length 3.8 to 4.2 times the depth. ig, 0.065-0.0685 mm. deep, length 4.3 to Fourth leg with trochanter 0.19-0.195 mm.

) times the depth; a long and slender tac- long, length 1.3 to 1.65 times the depth; e seta inserted 0.165-0.19 mm. from the pars basalis 0.145-0.16 mm. deep; pars oximal margin of the tarsus. tibialis 0.17-0.19 mm. deep; entire femur Genital Complex.—Anterior operculum 0.48-0.515 mm. long, length 2.6 to 3.0 times th usually 8 to 12 marginal setae near the depth; tibia 0.36-O.39 mm. long, 0.1-

E anterior margin of the genital aperture 0.112 mm. deep, length 3.35 to 3.85 times d with as many as 30 setae more anteri- the depth; tarsus 0.285-0.31 mm. long, ly located on the operculum; posterior 0.069-0.075 ram. deep, length 4.0 to 4.45 ereulum with 6 to 10 setae on the posterior times the depth; sensory seta 0.175-0.195

I of the genital aperture and 8 to 10 widely mm. from proximal margin of tarsus. |)arated and very slender setae in a trans- Genital Complex.—Anterior operculum rse row between the genital slit and the with between 20 and 25 (in one individual sterior margin of the operculum. only 17) setae arranged chiefly in a medi- Female.—Measurements and ratios based ally placed triangular group; posterior oper- four individuals, including the allotype, culum with six or eight widely scattered general, much like the male; body length setae arranged in a single marginal row. J5-2.20 mm.: carapace 0.675-0.75 mm. Tritoxv.mi'h.—Description based on two ig, width 0.85 to 0.95 times the length individuals. Measurements of one arc given ular width 0.32-0.34 mm.; abdomen 1.15- in parentheses after the corresponding JO mm. long, 0.9-1.05 mm. wide. measurements of the other whenever the Chelicera.—Similar to the male; 18 to 19 two differ significantly. Same general fea- stes in the serrula exterior; length of tures as in the adult except that the body elicera 0.2-0.215 mm., width of base 0.13- is less darkly colored and less sclerotic; 14 mm., length of movable finger 0.175- length 1.65 mm. Carapace light yellowish- 19 mm. brown; white blotches near the posterior Palp.—Segments slightly larger than in margin fused medially to form a single e male but the length-width ratios almost transverse bar anteriad to and isolating a entical in the two sexes; maxilla 0.33-0.35 small median pigmented area lying near the m. long, 0.25-0.28 mm. wide, length 1.2 posterior margin of the carapace; carapace 1.45 times the width; trochanter 0.26- 0.55 (0.575) mm. long, with the greatest 27 mm. long, 0.18-0.195 mm. wide, length width but little less than the length. Abdo- ?5 to 1.45 times the width; femur 0.52- men much as in the adult; tergites, however, 535 mm. long, 0.215-0.225 mm. wide, lighter in color and less sclerotic; setae of ngth 2.35 to 2.5 times the width ; tibia tergites less clavate and in some cases almost 48-0.495 mm. long, 0.235-0.25 mm. wide, acuminate; sternites as in the adult except ngth 1.95 to 2.05 times the width; chela, less darkly colored, not so coarsely granular, ithout pedicle, 0.865-0.885 mm. long, 0.34- and with fewer setae. .?75 mm. wide, length 2.37 to 2.55 times Chelicera.—In general with the character- e width ; chelal hand exclusive of pedicle istics in the adult; serrula exterior with 16 47-0.485 mm. long, 0.34-0.38 mm. deep; or 17 ligulate plates; chelicera 0.16 (0.17) ovable finger 0.445-0.465 mm. long. mm. long, base 0.1 (0.11) mm. wide, mov- eeth, both marginal and accessory, much able finger 0.15 mm. long. — —

460 Illinois Natural History Survey Bulletin lol. 24, Art. 4

Palp.—In general shape, chaetotaxy, and and sycamore branches, Sept. 22, 1908, L. N. sculpturing much as in the adult; the pedi- Smith, 11 nymphs and adults. Centralia: cles of the femur and tibia are much wider under pear bark, June 18, 1947, L. J. Stan-

than long and poorly separated from the nard, 1 o . Fowler: same data as for holo- rest of the segment; tibia a little stouter type, 1 $ (jc). Karnak: same data as for and the chela a little more slender than in allotype, IV. Lake Glendale: groi:nd

the adult. Maxilla 0.285 mm. long, tro- cover, March 17, 1943, Ross & Sanderson, 1 chanter 0.205 (0.215) mm. long, femur 0.38 nymph. Marshall: under bark of living

mm. long; tibia 0.355 (0.34) mm. long, oak tree, Oct. 10, 1908, H. E. Ewing, I ,_' 0.195 mm. wide; chela 0.695 (0.675) mm. (cu). Quincy: near Benton's Cave, inner long, 0.262 (0.258) mm. wide; chela depth layer of bark on log, April 27, 1944, C. C

about 0.26 mm., hand length 0.37 mm.; mov- Hoff, 1 S (ch) ; nest in bluebird box, Oct. able chelal finger 0.36 (0.35) mm. long. 30, 1945, T. E. Musselman, 1 nymph (ch). Marginal teeth, fig. 32D, of each finger be- Urbana: under bark of maple, June 18,

1 tween 25 and 30 in number ; the distal 8 1942, K. M. Sommerman, 3 ; under barlr,

to 12 teeth of the marginal row of each July 20, 1944, K. M. Sommerman, 1 9 . finger acute and with well-formed cusps, This species is usually found under the other teeth blunt, rounded, with very weak bark of deciduous trees or logs but may oc-

cusps or without cusps ; accessory teeth casionally be taken in woody debris and fewer in number and more weakly developed forest ground cover. The tritonymph col- than in the adult. The three tactile setae lected at Quincy by T. E. Musselman was of movable finger as shown in fig. 32D. taken from a nest in a bluebird box. Fixed finger with four tactile setae in external series, arranged much as in the adult 13. CHELANOPS Gervais male; internal series of three tactile setae Chelanops Gervais, in Gay (1849, p. 13). with It slightly more than twice as far from Genotype, monobasic: Chelifer (C/ielatiops) the finger tip as from the level of et and loeciu Gervais. of est; isb somewhat distad from the level Chelanops Gervais. Beier (1932f, p. 177),

and ib as in the adult ; Ist wanting. Hoff (1947, p. 503). Legs.—In general as in the male, except Carapace somewhat longer than wide, segments a little stouter, lighter in color, granular; tergites divided, granular. Setae less sclerotic, and with fewer setae. First of body and palps somewhat variable, plu- leg with entire femur about 0.25 mm. long; mose, and usually appearing subclavate to tibia with extensor margin straight except clavate. Flagellum with four setae. Palp, long, at the proximal end, 0.18 (0.175) mm. fig. 33, moderately heavy, granular; tactile the tarsus length 2.6 (2.4) times depth; seta ist placed on the same level with est or both margins more convex than in the with a little proximad from est; st nearer to / adult, 0.185 (0.19) mm. long, length about than to sb. Tarsus of fourth leg without a 3.2 times the depth. Fourth leg with pars tactile seta. basalis about 0.13 mm. deep; pars tibialis 0.15 (0.155) mm. deep; entire femur 0.375 mm. long, length 2.5 (2.4) times the depth; tibia with extensor margin almost straight, 0.29 (0.277) mm. long, 0.087 (0.08) mm. deep; tarsus with both margins conspicuously convex, 0.22 (0.225) mm. long, about 0.075 mm. deep; sensory seta of tarsus shorter than in the adult and inserted 0.115 (0.13) mm. from the proximal margin of the segment. Holotype, male.—Fowler, Illinois: bark of oak tree, July 19, 1944, C. C. Hoff. Allotype, female.—Karnak, Illinois: Feb. 24, 1933, Ross & Mohr.

Paratypes. Illinois.—Arcola : under bark, June 12, 1908, H. E. Ewing, 19 Fig. 33. Chelanops ajfinis $ . Dorsal view (mcz). Carbondale: jarred from willow of palp (setae omitted). ;;

Jutic, l^M9 Hoff: Pseudoscorimo.vs of Iiiinois 461

The genus is confined to the Americas, also a distinct difference between the two chiefly South and Central America and the species in the amount of flattening of the West Indies, and, as now limited, contains outer margin of the chelal hand, our Illi- a small number of species. One species, nois species, fig. 28, having a much more Chelanops affinis Banks, is recorded from flattened margin than does scorpioides as Florida. Many species were assigned to figured by Beier (I932<-). An atypical male (Chelanops by earlier authors, but most of in one of the collections appears to resemble them have been transferred to other genera. the male of scorpioides as figured by Beier (1932f), but the length of the palpal seg- 14. PSELAPHOCHERNES Beier ments and the somewhat flattened external

Pselaphocheini-s Beier (1932r, p. 130), (1933, margin of the chelal hand indicate that the p. 520). Genotii-pe, by original designation: individual is not scorpioides. Chelijcr scorpioides Hermann. M.ALE.—Measurements and ratios arc Cephalothorax somewhat longer than based on four individuals. Body moderately stout; « ide, fig. 34D, fairly well granulated ; setae yellow in color except for light brown of body and palps moderately long, toothed, or golden colored palps; 1.5-1.9 mm. long; carapace, fig. and often lightly clavate : three blades in 34D. with straight to slightly the cheliceral flagellum; a single internal convex posterior margin and with 8 to 10 accessory tooth on each chelal finger; fixed marginal setae; anterior margin bluntly finger with short and vestigial venedens and rounded and with four setae; anterior half duct; tactile seta ist of the fixed finger on of each lateral margin convex, posterior about the same level as est. Internal series half of lateral margins straight and parallel; of tactile setae not forming a basal group, median and posterior transverse furrows fig. 34B; seta st a little nearer to / than to not well marked; surface moderately granu- sb or about midway between the two; tar- lar, light brown in color; numerous setae sus of fourth leg with a tactile seta near scattered over the face and sides; setae sub- the mid-point or slightly proximad from the clavate, with a few terminal denticulations mid-point of the segment. no eye spots; length of carapace 0.53-0.61 Except for a doubtful record of the Euro- mm., greatest width 0.45-0.51 mm. near pean scorpioides from the eastern United center, posterior width almost equal to the

States, only the following species is known greatest width. Abdomen 0.95-1.3 mm. long, from the nearctic region. 0.6-0.72 mm. wide; length 1.5 to 1.8 times the width. Tergites weakly sclerotic, in- Pselaphochernes parvus Hott conspicuously divided except the eleventh Pselaphnchernes parvus Hoff (194Sa, p. 38). half-tergites each usually with five to seven Diagnostic characters of the species are (occasionally eight) widened and terminally illustrated in fig. .54. A full description of paucidenticulate setae. Sternites 4 through the female is given in the original descrip- 10 divided, most half-sternites with from tion. Study of the present material has 9 to 1 1 (occasionally more) acuminate setae, brought to light the undescribed male of chiefly confined to a marginal row ; fourth the species and has led to a clearer demon- sternite with three to five setae forming a stration of the differences between parvus marginal row in each half-sternite. Pleural and the closely related European species, membranes marked by wavy, subpapillose, scorpioides (Hermann). Several character- longitudinal plications. Each anterior stig- istics that can be expressed numerically matic plate with one seta; each posterior serve to separate the two forms. The chela plate with two. of the female of parvus has a length 2.9 to Chelicera. — Length 0.175-0.195 mm., 3.15 times the width, while in scorpioides width 0.11-0.125 mm., the laminal and in- the chela is 2.7 times as long as wide; in the terior setae acuminate, simple, much longer male of parvus the femur is 0.45-0.51 mm. than the basal and subbasal ; basal, subbasal, long, in scorpioides 0.43 mm.; the chela of and exterior setae denticulate along the dis- the male of parvus is 3.1 to 3.2, but in tal fourth. Flagellum of three blades, the scorpioides 2.9. times as long as wide ; in distal one bearing 10 to 12 denticulations parvus the movable chelal finger of the male on the anterior edge along the distal two- is 0.41-0.45 mm. long, in scorpioides 0.38 thirds. Fixed finger with well-developed mm. Measurements for scorpioides have lamina exterior; the serrula interior with been taken from Beier (1932c). There is five free and serrate marginal teeth, remain- —

462 Illinois Natural History Survey Bulletin Fol. 24, Art. der fused into a velum; apical tooth with margin weakly S-shaped; length measuri two or three internal denticles; the internal along the extensor margin 0.45-0.51 mn margin of finger with six or seven denticles maximum over-all length a little greatc arranged along the distal one-third of the 0.17-0.195 mm. wide; length 2.55 to 2.( finger. Movable finger, fig. 34/^, 0.173- times the width. Tibia slightly shorter ar 0.185 mm. long; serrula exterior of 18 ligu- wider than the femur; granulations ar late plates, the basal one or two but little chaetotaxy much as in the femur; extensi longer than the remainder; subapical lobe margin somewhat flatly convex but mo close to end of finger and subequal in size convex toward the distal end; flexor marg to the apical or terminal tooth; galeal seta bulging in the center; 0.435-0.485 mm. Ion extending just beyond the tip of the galea; 0.185-0.215 mm. wide; length 2.23 to 2.'. galea less well developed than in the female, times the width. Chela moderately slende usually with two main rami, each of which hand granulate and with long subacumina is in turn branched or bifurcated. setae, each with one or two subtermin Palp.—Fig. 34C. Moderately granular denticulations; outer margin of chela flat except that the fingers are smooth and the convex, inner margin more convex ; finge flexor surfaces of the femur and tibia are curved; chela 0.75-0.83 mm. long, 0.24-0.; coarsely granular; setae subclavate to acu- mm. wide, length 3.1 to 3.2 times the widtl minate. Maxilla with scattered acuminate 0.235-0.27 mm. deep; hand length withoi setae; 0.275-0.31 mm. long; length about pedicle 0.385-0.43 mm. ; finger slightly longi 1.5 times the width. Trochanter with two than hand without pedicle, measuring fro protuberances, coarsely granular; numerous 0.41-0.45 mm. Viewed laterally, fig. 34 niultidenticulate setae on inner surface; both dorsal and ventral margins of hat length 0.255-0.275 mm., 1.45 to 1.55 times appear convex. Each finger with betwei the width. Femur with pedicle about as long 35 and 45 marginal teeth, contiguous, at as wide; extensor margin convex and with with well-developed cusps ; a single interii numerous setae varying from short and accessory tooth on each finger, locat< niultidenticulate near the base to longer and slightly more than one-fourth of fingi paucidenticulate near the distal end; flexor length from the tip ; usually seven or eigi surface coarsely granular and with a few exterior accessory teeth on each finge setae like those of the trochanter; flexor spaced along the distal three-fourths of tl

Fig. 34. Pselapliochernes parvus $. A, tip of movable cheliceral finger; B, lateral vie of chelal hand; C, dorsal view of palp; D, dorsal view of carapace. I ;

1949 HoFF: PSEUDOSCORPIONS OF Il.I.IXOlS 463 nger length. Tactile setae ot clielal fingers depth; sensory seta of the extensor surface i shown in the figure. of the tarsus located proximad from the Legs.—Yellow to very pale brown in mid-point of the segment, usually little more )lor: moderately slender; siibterminal setae than 0.4 of the tarsus length from the prox- id tarsal claws simple and entire; surface imal margin. sually weakly marked by scalelike lines; Giiiiltil C.fimplrx.—Anterior operculum •tae varying from paucidenticulate to with about 20 setae arranged in a crescent; ;uminate. First leg with trochanter about posterior operculum with 8 to 10 (rarely 12 mm. long, several relatively long pauci- 12) marginal setae; four (rarely five or six) enticulate setae on flexor surface as well setae on the posterior lip of the genital open- i a long acuminate pseudotactile seta; pars ing, almost within the opening, and anteriad iisalis 0.125-0.135 mm. long, length 1.2 to to the marginal row. ,4 times the depth; pars tibialis with a I'EM.M.i:.— Females much more numerous eakly convex extensor margin, flexor mar- than males. Female differing but little from in more weakly convex and almost straight, male; slightly larger, up to 2.2 mm. or more !tae of extensor margin short and pauci- in length, often a little more darkly pig- enticulate, those of flexor surface slightly mented than the male. Carapace and abdo- ingcr and almost acuminate, length of pars men not distinctly different in the two sexes. bialis 0.183-0.23 mm., depth 0.08-0.114 Chiiuira.—Slightly larger and with the im., length 2.0 to 2.3 times the depth; tibia galea more branched than in the male ; other- ith a very weakly S-shaped extensor mar- wise almost identical in the two sexes.

In, flexor margin weakly convex, chaetotaxy Palps.—Most segments, especially the

> in the pars tibialis, tibia 0.23-0.26 mm. chela, slightly larger than in the male; other- ing, 0.065-0.077 mm. deep, length 3.35 to wise similar. Chela (measurements based on 55 times the depth; tarsus with flexor mar- 16 Illinois specimens) exclusive of pedicle in slightly convex, extensor margin nearly 0.85-0.95 mm. long, 0.27-0.31 mm. wide, raight, setae more numerous than on other length 2.9 to 3.15 (rarely less than 3.0) gments, setae varying from terminally and times the width; movable finger 0.45-0.51 ibterminally denticulate on the basal part mm. long. Teeth and tactile setae of chela f the extensor surface to truly acuminate as in the male; length-width ratios of chelae

1 the terminal portion of the segment of Illinois specimens on the average slightly irsus 0.2-1-0.27 mm. long, 0.05-0.054 mm. less than the ratios for the type specimens :ep, length 4.6 to 5.1 times the depth, from Arkansas (Hoff 1945a). ourth leg with chaetotaxy and sculpturing Li'ffs.—Shape, chaetotaxy, and sculptur- i in the first leg; trochanter with numerous ing essentially as in the male ; segments, ;tae, especially on the flexor surface, length however, frequently larger; length-depth ,16-0.17 mm., 1.35 to 1.45 times the depth; ratios about the same in the two sexes. The irs basalis subtriangular, distal three- following measurements and ratios of cer- jurths of flexor margin straight, flexor sur- tain pedal segments in the female are based ice with numerous long and subacuminate on measurements of nine individuals: tibia ;tae, length 0.16-0.175 mm., 1.3 to 1.45 of first leg 0.255-0.295 mm. long, 0.072- mes the depth pars tibialis extensor 0.08 mm. deep, length 3.4 to 3.85 times the ; with largin evenly and moderately convex, flexor depth; tarsus of first leg 0.27-0.3 mm. long. largin straight and continuous with that of 0.053-0.059 mm. deep, length 4.6 to 5.2 times le pars basalis; pars tibialis 0.3-0.35 mm. the depth; pars tibialis of fourth leg 0.35- ing, 0.122-0.15 mm. deep, length 2.3 to 0.4 mm. long, 0.135-0.155 mm. deep, length .45 times the depth; entire femur 0.42- 2.45 to 2.75 times the depth; tibia of fourth .48 mm. long, length 3.2 to 3.45 times the leg 0.345-0.385 mm. long, 0.09-0.1 mm. as as epth ; tibia with weakly S-shaped extensor deep, 3.7 to 4.2 times long deep. largin and convex flexor margin, length Genital Complex.—Anterior operculum

.5 to 3.85 times the depth; tarsus with both with 14 to 18 setae; posterior operculum exor and extensor margins weakly convex, with 8 or 10 setae. ightly narrowed distally, deepest near the Tritonymph.—Measurements are based :vel of the sensory seta, chaetotaxy much on three individuals mounted in balsam.

5 in the tarsus of the first leg, 0.26-0.315 Much like the adult but smaller and lighter im. long, 0.065-0.07 mm. deep, length 4.4 in color; appendages stouter. Body 1.35- 4.0 in one individual) to 4.75 times the 1.55 mm. long; carapace about 0.5 mm. long 404 Illinois Natural History Surnev Bulletin I'ol. 24, An. 4

and about 0.4 mm. wide ; abdomen between the deutonymph ; body length about 0.9 mm. 0.6 and 0.7 mm. wide. Chelicera essentially Serrula exterior of the movable cheliceral as in the adult. Palpal segments conspicu- finger apparently of 11 plates. Chela ex- ously and coarsely granular on the flexor clusive of pedicle about 0.4 mm. long, about surfaces, other surfaces moderately granu- 0.14 mm. wide; chelal hand exclusive of lar; chelal hand moderately granular; tro- pedicle 0.21 mm. long; movable finger equal chanter 0.22-0.23 mm. long, 0.13-0.14 mm. in length to length of hand exclusive of wide; femur with maximum length between pedicle. Movable finger with one tactile 0.33 and 0.35 mm., length along the extensor seta, probably st, located about two-fifths margin 0.3-0.32 mm., width 0.14—0.15 mm., of the finger length from the proximal finger greatest length 2.3 to 2.5 times the width, margin. Fixed finger with one tactile seta, length along the extensor margin 0.21 to probably est, located somewhat distad from

0.23 times the width ; tibia about 0.33 mm. the mid-point of the finger and one basal long, 0.16 mm. wide; chela 0.61 ram. long, seta of the external series located near the 0.205-0.21 mm. wide, length between 2.9 finger base; internal series represented by a and 3.0 times the width; depth of chelal single tactile seta located about on a level hand subequal to the width; chelal hand 0.32 with the single basal seta of the external mm. long; movable chelal finger 0.29-0.31 series. mm. long. Tactile setae of the chelal fingers Distribution.-—Known only from much as in the adult except b is missing from Arkansas and Illinois; taken from scattered the movable finger and isi is wanting from localities in all areas of the latter state. the fixed finger; also it is much closer to the Habitat data are available for 25 collec- level of est than to the level of et, while in tions. Sixteen of these collections were made the adult it is closer to the level of et than from rotting logs or hollow trees and, in two to the level of est. Marginal and accessory of these, nests of small mammals were pres- chelal teeth much as in the adult except ent. The other collections were made from fewer in number. woody debris and ground cover. The col- Deutonymph.—Two specimens exam- lections indicate a decided association with ined. Smaller than the tritonymph but same retting wood as a preferred habitat. general characteristics. Body length 1.0— Illinois Records.—Thirty collections, 1.05 mm., carapace about 0.38 mm. long. taken throughout the year, are from Cache, Serrula exterior of the movable cheliceral Caledonia, Elk Grove, Elsah, Grand finger with 14 or 15 ligulate plates. Palpal Tower, Harrisburg, Herod, Kampsville, segments smaller than in the tritonymph but Karnak, La Rue, Makanda, Monticello, with about the same length-width ratios. Mount Olive, Pere Marquette State Park, Palp with the following measurements Quincy, Sherman, Urbana.

(based on two individuals) : trochanter about 0.17 mm. long, 0.1 mm. wide; femur 15. DENDROCHERNES Beier with greatest length between 0.24 and 0.25 Dendrocherties Beier (1932f, p. 171). Geno- mm., width 0.11 mm.; tibia 0.23 to 0.24 mm. type, monobasic: Oicrnes cyrneus L. Koch. long, 0.12 mm. wide; chela exclusive of pedi- Dendrochernes Beier. Hoff (1947, p. 536). cle 0.45 to 0.46 mm. long, 0.148-0.155 mm. Carapace almost quadrate or a little wide, length 2.9 to 3.1 times the width; longer than wide, weakly to moderately chelal hand with length of 0.24 mm., depth granular, the posterior transverse furrow about equal to the width ; movable chelal nearer to the posterior carapacic margin finger 0.22 mm. long. Movable chelal finger than to the median transverse furrow. Ter- with two tactile setae: one, probably st, near gites except the eleventh divided, finely to the mid-point of the finger and the second, moderately granular. Setae of the body and probably sh, near the proximal margin; palps toothed, not appearing clavate. Flagel- nodus ramosus a little distad from st. Fixed lum of four setae. Palp heavy, fig. 35, chelal finger with tactile setae much as in finely to moderately granular; tactile seta the tritonymph but with both ist and one of ist is almost at the same level as est, st is the external series, probably esb, wanting. nearer to sb than to t. Tarsus of fourth leg Accessory teeth of chelal fingers apparently with a sensory seta distad from the mid- wanting. point of the segment.

Protonymph.—Somewhat smaller and The genus is holarctic in distribution. In with conspicuously stouter appendages than North America, Dendrochernes morosus — — —

•, 1949 Hoff: PsEunoscoRi'ioNs of Illinois 465

and sb or somewhat closer to / than to sb, ist of fi.\ed chelal finger distad from est, figs. iiiA, ilB; setae of palp subclavate to clavate; little sexual dimorphism exhibited by palp; fi.xed chelal finger with reduced venedens and short vestigial venom duct, fig. ibB. Fourth leg with no true tactile seta on the tarsus, but with a denticulate pseudotactilc seta near the distal end. Seminal receptacle of the female in the form of a long and slender tubule with a terminal sac or bulb. Genotype. Ri

Because it lacks a tactile seta on the tarsus of the fourth leg, the present genus ap- Fig. 35. Dendroi hirnes mnrosus 9 . l")orsal ew of palp (setae omitted). pears closely related to the genus Hespfro- thernts Chamberlin, hut differs in having

Hanks) is recorded from Isle Royale, Lake the tactile seta b of the cheliceral hand iperior. acuminate and not denticulate as in Hes- perocherins. The genus Reginachernes also 16. REGINACHERNES new genus bears some resemblance to Allocheriies Bcier, the two genera differ in number of setae Di.ACNOSls.—Cheliccra with fiagellum of but in the cheliceral fiagellum. lur setae; seta b of cheliceral hand acu- inate, sb stout and suhterminally denticu- Key to Species te, tig. ibD ; subapical lobe of movable Length of chela exclusive of pedicle less than leliceral finger well developed, figs. 36£, 0.9 mm., length of femur less than 0.55 mm. 'C, finger-like, and conspicuous; galea ewingi out, with several simple terminal and sub- Length of chela exclusive of pedicle more than rminal rami. Palp stout; tactile seta st 0.9 mm., length of femur more than 0.55

movable chelal finger midway between i mm lymphatus

Fig. 36. Rrginachernes eiiinffi, holotype 9. !, lateral view of chela; B, end of fixed lelal finger to show vestigial venedens; C, dorsal view of palp; /J, tactile seta sb of the leliceral hand ; F.. tip of movable cheliceral finger. ;

466 >]ois Natural History Survey Bulletin lol. 24, Art. 4

Reginachernes ewingi new species strong and one or two very weak denticles on the inner finger margin near the distal Only two individuals, one male collected end; lamina exterior evenly convex. Mov- one by Ewing more than 30 years ago, and able finger stout, fig. 36£ ; subapical lobe female, are available for study. Since the located near the base of the apical tooth; male is not in good condition for detailed galeal seta not reaching to the tip of the examination, the female has been designated galea; galea fairly stout and straight, with as the holotype fig. 36. The specimen col- apparently six simple rami in the distal half; lected by Ewing and deposited at the Muse- scrrula exterior of 17 ligulate plates; mov- um of Comparative Zoology has, according able finger about 0.16 mm. in length. to data accompanying the slide, been assigned Palp.—Fig. 36C Maxilla with numerous successively to the species Chclanops rnoro- acuminate setae and with all except the sus Banks and Chelanops sanborni (Hagen). ventral face moderately granulate; the tro- The specimen appears to be more closely chanter, femur, and tibia weakly to moder- related to Hesperochernes sanborni as re- ately granular and with numerous clavate described by Hoff (1946fl) than to Dendro- setae, the setae ranging from strongly cla- chernes niorosus as also redescribed by Hoff vate on the trochanter and femur to weakly (1947), but belongs to neither of these clavate on the extensor surface of the tibia; species. The present specimen appears not chela weakly granulate on the flexor sur- to have been reported by Ewing ( 1911 ) under face, setae more clavate on the flexor than either Chelanops morosus or sanborni, since on the extensor surface; fingers almost the only specimens collected at Areola and as- smooth and with numerous acuminate setae. signed by Ewing to the genus Chelanops Maxilla 0.34 mm. long, 0.24 mm. wide. were listed as Chelanops pallidas. It is pos- Trochanter with very globose protuberances, sible that this specimen was not included in little elevated; pedicle almost as long as report in 1911. the made by Ewing wide ; 0.34 mm. long, 0.205 mm. wide. Female.—Body and appendages fairly Femur with pedicle well separated from the stout; abdomen, carapace, and legs brown; rest of the segment and a little wider than palps deeper golden brown ; length of body long; flexor margin weakly convex except about 2 mm. Carapace rounded anteriorly on the distal one-third; extensor margin a and laterally; surface coarsely granulate; little convex; 0.48 mm. long, 0.21 mm. wide. anterior margin with 4 and the posterior Tibia with a stout pedicle; flexor margin margin with 8 to 10 setae; all carapacic bulging in the center but flattened beyond; flatly convex the central setae distinctly clavate ; greatest width near extensor margin in the center of the carapace, slightly narrower portion ; setae much less clavate on the ex- behind; length of carapace 0.65 mm., great- tensor than on the flexor surface; 0.48 mm. est width 0.66 mm. (or a little less, as the long, 0.22 mm. wide. Chela with pedicle carapace may be somewhat flattened from near center of base; extensor margin flatly mounting) posterior width 0.64 mm. Ter- flexor margin much more convex; ; convex, gites a little deeper brown than the cara- fingers slender and gently curved; chela, pace; interscutal areas subpapillose and not without pedicle, 0.85 mm. long, 0.31 mm.

pigmented ; each tergal half with five to wide; hand, without pedicle, 0.415 mm. long,

eight distinctly clavate setae. Sternites 0.3 mm. deep ; movable finger 0.455 mm. almost smooth, brown in color, all except long. Viewed laterally, fig. Z6A, chelal hand the tenth divided and with scuta well sepa- fairly stout, pedicle displaced a little to- little rated; tergite 4 with nine setae; maximum ward the ventral side ; ventral margin number of setae on any sternal half is 10; convex, dorsal margin more convex; basal

all sternal setae acuminate. Pleural mem- margin rounded ; the fixed finger nearly branes with wavy, almost papillose, stria- straight, the movable finger a little curved. tions; each anterior stigmatic plate with Tactile seta as shown in the figure. Fixed three setae, each posterior plate with two. chelal finger with a reduced venedens, fig. a short vestigial venom duct; Chelicera.—Yellow in color ; fairly stout 36S, and palm of hand with netlike markings; longest nodus ramosus of movable finger between flagellar seta serrate along almost the entire one and two areolar diameters basad from anterior edge. Fixed finger with two or tactile seta /; marginal teeth of both fingers three weak and rounded denticles on the contiguous and cusp-bearing, between 30 inner margin of the apical tooth and two and 35 in number; three or four internal —

une, 1949 Hoff: Pseudoscorpions of Illinois 467 id the same number of external accessory eth on each finger. Legs.—Setae of legs variable; those of the :tensor surface of segments chiefly clavate, hers subclavate to acuminate; segments )parently smooth. First leg with pars isalis 0.122 mm. deep; pars tibialis with )th margins evenly convex, 0.1 13 mm. deep; itire femur with most setae subclavate to avate, 0.34 mm. long; tibia stout and very eakly S-shaped. 0.247 mm. long, 0.087 mm.

•ep ; tarsus with setae of extensor surface uminate, extensor margin nearly straight, •xor margin very weakly convex, deepest

the basal third and tapering a little to- ard the distal end, 0.27 mm. long, 0.065 m. deep. Fourth leg with setae of the ochanter, the pars hasalis, and the flexor rface of the tarsus acuminate; setae of the tensor surface of the tibia and tarsus rongly clavate ; setae of the flexor surface the pars tibialis and tibia weakly clavate acuminate; pars basalis 0.145 mm. deep; tire femur with the flexor margin evenly id weakly convex, the extensor margin jll rounded and evenly convex, margins the two femoral parts continuous; entire mur 0.46 mm. long, 0.155 mm. deep; tibia uch more slender than that of the first

I and a little S-shaped, 0.365 mm. long, )95 mm. deep; tarsus narrowing gradu- ly toward the distal end, 0.305 mm. long,

)7 mm. deep ; a suhtactile clavate seta igcr than the other investing setae located Fig. 37. Reijina< hemes lymfliatus. A, dor-

sal view of palp, holotype ; B, lateral tt'ard the distal end of the extensor margin 9 view of chelal hand, allotype ; C, tip of movable the tarsus. i cheliceral finger, holotype $ ; D, apical setae Genital C.umplex.— Posterior margin with of extensor surface of tarsus IV', holotype 9. setae forming a single row; anterior erculum with about 20 setae irregularly elusive of pedicle about 0.4 long, ranged in a group anteriad to the genital mm. mov- erture. able finger 0.46 mm. long. Fourth leg with entire femur 0.46 mm. long, 0.15 M.ALE.—The single known male, the allo- mm. deep; tibia 0.36 mm. long, 0.09 deep; 3e, not in a favorable condition or position mm. tarsus 0.31 mm. long and 0.07 deep. r study, having been mounted in an un- mm. Details of genital complex not discernible ssected condition by Ewing. As near as in specimen. n be determined, structural details are Holotype, .Muncie, ;ntical in the two sexes except that the female.— Illinois, Sept. 19, 1943, H. H. Ross. da is a little stouter and the tactile seta Allotype, male. Areola, Illinois, July of the movable chelal finger is relatively — 21, 1909, H. E. Ewing (.mcz). (ser to / and farther from sb in the male, The holotype was collected easurements secured from the male as from leaf mold and the allotype Hows: carapace 0.65 mm. long, 0.67 mm. was secured from beneath the barLof an oak tree. de ; palpal trochanter 0.34 mm. long and 105 mm. wide; femur 0.49 mm. long. 0.21 Reghiachernes lyinphatus new species n. wide; tibia 0.48 mm. long, 0.215 mm. de; chela exclusive of pedicle 0.85 mm. Reginaehernes tymphatus, figs. 37//-37Z), ig and 0.32 mm. wide; chelal hand ex- may be separated from ewingi by characters 468 Illinois Natural History Survey Bulletin Fol. 24, An. 4

given in the key. The palp of lympliatiis der; lamina exterior well developed and has considerable similarity to the palp of evenly convex; inner margin of apical tooth Chelanops corticis Ewing, as figured by with three small denticles, inner margin of

Ewing (1911, fig. 9). Our form, however, finger with two strong and two weak den- differs in many ways from the text descrip- ticles near the distal end. Movable finger, tion given by Ewing with respect to the fig. 37 C, fairly stout; subapical lobe inserted cheliceral galea, the investing setae of the near the base of the apical tooth and much palps, and other details. There is a possi- distad from the insertion of the galeal seta; bility that some of these characters may one or two minute denticles on the inner have been misinterpreted, in which case finger margin near the level of the insertion lymphatus may really be corticis. To date of the galeal seta; galeal seta not reaching the type material of corticis has not been to the tip of the galea; galea fairly stout, located ; so its identity cannot be established. with six simple and distally acute rami con- Female.—Observations and measure- fined to the distal one-half of the galea; ments are based upon the female holotype serrula exterior of 17 or 18 ligulate plates; and one female paratype unless otherwise length of movable cheliceral finger about indicated. Body and legs light brown, palps 0.19 mm. golden brown ; body stout ; length of body Palp.—Fig. 37J. Measurements and (four females measured) between 2.4 and ratios of the palpal femur, tibia, and chela 2.6 mm., the holotype with the abdomen (except the depth) given as the range of contracted measuring only 1.95 mm. Cara- four individuals (the holotype and three pace stout; anterior half with rounded mar- female paratypes), of which two are in alco- gins, posterior portion with sides almost hol. Stout, fairly deep brown to reddish parallel; surface moderately to coarsely or golden brown in color; the sides of the granular, appearing more weakly granular maxilla and the entire trochanter and femur on the dorsal surface; setae scattered, fairly moderately to coarsely granular; the flexor numerous, distinctly clavate; posterior trans- surface of the tibia moderately granular; verse furrow much closer to the posterior the flexor surface of the chelal hand weakly carapacic margin than to the median furrow; ' to moderately granular; setae of the tro- posterior carapacic margin with 10 to 12 chanter and the flexor surfaces of the femur clavate setae; eye spots not observed; length and tibia heavy and chiefly clavate; setae of of carapace about 0.85 mm., greatest width the extensor surface of the femur and tibia about 0.75 mm. Tergites of abdomen brown less strongly clavate and sometimes pauci- in color, all divided e.xcept the eleventh, with denticulate; setae of the flexor surface of the interscutal membranes very rugose; ter- the chelal hand subclavate, those of the gites fairly granular; setae clavate, usually extensor surface paucidenticulate ; setae of seven setae on each scutum of first tergite the fingers acuminate. Maxilla about 0.4 and eight setae on each scutum of the second mm. long and 0.3 wide. Trochanter in strict tergite, ma.ximum number of setae on any dorsal view very stout; subdorsal protuber- tergal half is 11. Sternites 4 through 10 ance rounded and not much elevated; tro- divided; interscutal spaces striate and ru- chanter of female paratype 0.42 mm. long, gose; sternal scuta brown in color, marked 0.24 mm. wide. Femur with pedicle little by scalelike lines; each half-sternite of the longer than wide; extensor margin of femur fourth abdominal segment with four to six very flatly convex, flexor margin weakly acuminate setae; maximum number of setae convex in the basal two-thirds but weakly on any sternal half is 17. Pleural mem- concave beyond ; measured along the ex- branes very rugose; each anterior stigmatic tensor margin 0.63-0.64 mm. long, 0.255- plate with two setae, posterior plate with 0.27 mm. wide, length 2.35 to 2.5 times the one; abdomen stout, usually about 1.5 mm. width. Tibia with extensor margin slightly long, about 1 mm. wide. flattened in the central portion ; flexor mar- Chi'licerii. of at —Fairly stout ; palm hand gin bulging and convex except the extreme with netlike markings; subbasal seta with a distal end where the margin is flattened or few minute terminal and subterminal den- very slightly concave ; 0.6-0.63 mm. long, ticulations; longest flagellar seta unilaterally 0.28-0.29 mm. wide, length between 2.1 and serrate, the serrations minute and widely 2.2 times the width. Chela with margins

spaced ; length of chelicera 0.22-0.24 mm., evenly convex, the flexor margin a little width of base 0.13 mm. Fixed finger slen- more convex than the extensor; base of hand June, 1949 Hokf: Pskuduscorhions ok Illinois 469

rounded; fingers fairly slender and sonie- deep; tarsus subcylindrical but tapefing a uliat curved; chela, without pedicle, 0.99- little toward the distal end, 0.34 (0.35) 1.02 mm. long, 0.37-0.,?8 mm. wide, length be- mm. long, 0,084 mm. deep; the extensor mar- tween 2.65 and 2.75 times the width ; chclal gin of the tarsus with a denticulate pseudo- hand e.xclusive of pedicle 0.52-0.55 mm. tactile seta, fig. 37Z), longer than the den- long, about 0..S3 mm. deep (depth deter- ticulate investing setae and located 0.2-0.22

mined for the hand of only one female) ; mm. from the proximal margin of the tarsus. movable finger 0.5-0.53 mm. long. Viewed Genital Complex.—About 12 to 15 mar- laterally, the base of the chelal hand appears ginal setae on the posterior operculum; rounded, the margins weakly convex, and nearly 20 setae grouped anteriad to the the pedicle displaced a little toward the aperture on the anterior operculum. ventral side; the fixed finger nearly straight, Male.— Unless otherwise indicated, de- the movable finger a little curved and ap- scription and measurements are based upon pearing weakly granulate on the exterior the male allotype. Body and carapace much surface. Tactile setae of chelal fingers as as in the female ; a few more setae on the fig. shown for the male, MB ; nodus ramo- fourth sternal halves and a few less on the sus of movable chelal finger varying from central sternal halves than in the female; a position about midway between tactile body of allotype 2.4 mm. long, of one para- setae / and st to a position much closer to type 2.15 mm. long; carapace and abdomen

St than to i. Each finger with about 40 as in the female. contiguous, conical, cusp-bearing marginal Chelicera.—As in the female. teeth; accessory teeth somewhat variable, Palp.—Chaetotaxy and sculpturing, as usually 8 to 10 in the external row of each well as the general appearance, much as in finger and 1 to 4 in the internal row; end the opposite sex except setae may be a little of fixed finger with a very poorly developed heavier and the palpal femur and chela ap- venedens containing a vestigial duct. pear to be a very little stouter. Measure- Legs.—Measurements relative to the ments based on two individuals (one in alco- holotype are followed in parentheses by the hol), the measurements of the male allotype corresponding measurements of the mounted followed in each instance by the correspond- female paratype whenever the two show a ing measurement of the male paratype, when- significant difference. Legs usually light ever a measurement was secured for the brown in color ; femoral parts and tibiae latter. Maxilla 0.38 mm. long, about 0.3 weakly granular, granules not easily ob- mm. wide; trochanter 0.43 mm. long, 0.25 served except on the pars tibialis; setae of mm. wide; femur measured along the ex- the extensor surface of the segments and in tensor margin 0.64 (0.6) mm. long, 0.27 part setae of flexor surfaces of femora (0.255) mm. wide; tibia 0.63 (0.6) mm. long, subclavate to paucidenticulate ; setae of the 0.295 (0.285) mm. wide; chela exclusive of flexor surfaces of the tibia and tarsus pedicle 1.06 (0.97) mm. long, 0.407 (0.38) acuminate and more numerous. First leg mm. wide; chelal hand exclusive of pedicle with pars basalis 0.152 (0.16) mm. deep; 0.55 (0.51) mm. long, 0.355 mm. deep; mov- pars tibialis 0.14 mm. deep; entire femur able finger 0.545 (0.51) mm. long. Tactile 0.44 mm. long, length 2.88 (2.75) times the setae, fig. 37/i, and teeth of the chelal fingers depth; tibia stout, deepest near the distal much as in the female. one-third, 0.3 (0.315) mm. long, 0.102 mm. Legs.—Essentially as in the female; deep; tarsus tapering a little toward the measurements secured only from the allo- distal end, subcylindrical, about 0.295 mm. type. First leg with pars basalis 0.15 mm. long, 0.065 (0.068) mm. deep. Fourth leg deep, pars tibialis 0.14 mm. deep; entire with pars basalis 0.182 (0.175) mm. deep; femur 0.44 mm. long; tibia 0.308 mm. long, pars tibialis 0.205 (0.192) mm. deep; femur 0.103 mm. deep; tarsus 0.285 mm. long, with extensor margin evenly convex, flexor 0.065 mm. deep. Fourth leg with pars margin very weakly convex to straight, basalis 0.164 mm. deep, pars tibialis 0.183 length of entire femur 0.595 (0.61) mm., mm. deep; entire femur 0.595 mm. long; length 2.9 (3.17) times the depth; tibia tibia 0.465 mm. long, 0.1 18 mm. deep ; tarsus much more slender than in the first leg, 0.345 mm. long, 0.084 mm. deep ; denticulate flexor margin a little convex, extensor mar- pseudotactile seta located 0.225 mm. from gin straight to a very little concave ; tibia proximal margin of tarsus. 0.46 (0.48) mm. long, 0.12 (0.114) mm. Genital Complex.—Posterior operculum —

470 Illinois Natural History Survey Bulletin I'ol. 24, Art. 4

with 24 scattered setae, some of which are with appendages stouter than in the trito-

arranjied along the posterior margin, and nymph ; most tergal scuta with five or six

four smaller setae just posteriad to the pos- clavate setae ; anterior stigmatic plate ap- terior rim of the aperture; anterior opercu- pears to have but one seta; length of body lum with 24 scattered setae. about 1.4 mm. Tritonymph.—Unless indicated to the Chelicera.—Smaller than in the trito- contrary, description is based on one tritonymph; subbasal seta simple; galea with nymph paratypc. Lighter in color, smaller probably three rami, terminal and subter- in size, and with stouter segments than in ininal in position. the adult. Chaetotaxy of the abdomen and Palp.—Segments much smaller, lighter in carapace much as in the adult but with a color, and with fewer and slightly weaker slightly smaller number of setae; body about setae than in the tritonymph; general shape 2 mm. long. very similar in the tritonymph and the deuto- Chelicera.—Much as in the adult except nymph. Measurements of one deutonymph smaller; the denticulations of the subbasal follow: femur 0.28 mm. long, 0.145 mm, seta almost wanting; galea more slender and wide; tibia 0.28 mm. long, 0.15 mm. wide; the rami confined to about the distal one- chela exclusive of pedicle 0.53 mm. long, third; serrula exterior of IS or 16 ligulate 0.185 mm. wide; chelal hand exclusive of plates. pedicle 0.275 mm. long, 0.175 mm. deep; Palp.—Chaetotaxy and sculpturing much movable finger 0.27 mm. long. Viewed later- as in the female, except the setae a little ally, dorsal margin of chelal hand appears less stout, color lighter; the palpal femur a much more convex than the ventral margin, little stouter but the chela more slender Movable finger with two tactile setae; one, than in the adult. Measurements of the probably st, a little distad from the mid- femur, tibia, chela, and movable finger are point of the finger and about one areolar the ranges secured from measuring three diameter proximad from the level of the individuals, of which two are unmounted. nodus ramosus; b as in the tritonymph, Femur 0.4-0.41 mm. long, 0.195-0.2 mm. Setae of the fixed finger considerably differ- wide; tibia 0.395-0.4 mm. long, 0.205-0.21 ent from those of the tritonymph ; it near mm. wide; chela exclusive of pedicle 0.7- the mid-point of the finger or a little prox- 0.73 mm. long, 0.25-0.255 mm. wide; mov- imad from the mid-point; et about midway able finger 0.37-0.39 mm. long; chelal hand between the finger tip and it; est about as exclusive of pedicle in the mounted paratype far from the finger base as et is from the 0.37 mm. long, 0.35 mm. deep. Movable finger tip; ib a little proximad from the finger with three tactile setae: / a little level of isb ; esb apparently wanting ; eb basad more than one-third of the finger length from the level of ib. Marginal teeth of the from the tip; b placed much as in the adult; chelal fingers much as in the tritonymph

St midway / between and b; sb wanting; except cusps less well developed ; accessory nodus ramosus about one areolar diameter teeth wanting except for a single internal proximad from the level of tactile seta t. accessory tooth near tip of fixed finger. Fixed finger with tactile setae much as in Ler/s.—Much like the legs of the trito- the adult except ist is wanting and it is nymph except less sclerotic, much smaller, relatively a little farther from the level of and with many segments probably a little et. Each finger with between 25 and 30 stouter. Pseudotactile seta of the fourth marginal teeth; each external row of acces- pedal tarsus denticulate in the mounted sory teeth with three to five teeth, internal deutonymph. row represented by one or two teeth ; fixed Holotype, female.—Urbana, Illinois: finger with weakly developed venedens and Brownfield Woods, Oct. 21, 1933, H. H. vestigial duct. Ross. Lejis.—Lighter in color, less sclerotic, and Allotype, male.—Mooseheart, Kane with fewer setae than in the adult; segments County, Illinois: Sept. 24, 1940, Henry stouter; tarsi more narrowed distally; Dybas (cm).

fourth tarsus with the denticulate pseudo- Paratypes. Illinois. Aurora: Sept. 4, tactile seta as described for the adult. 1939, Henry Dybas, 4 tritonymphs, 2 deuto-

Measurements not secured. tri- nymphs (cm) ; April, 1940, IS, 19,2 Deutonymph.—Description based on one tonymphs (cm). Mooseheart: same data individual. Smaller, lighter in color, and as for allotype, 2? (cm). —

W4':i Hoff: Pseuuoscorpions of Illinois 471

The holotype was taken from soil-cover acters are illustrated in figs. .^8/V-C'; a more iiples in oaic-hickory woods. nearly complete description has been given previously by the writer (Hoff 194b/). 17. PSEUDOZAONA Beier tuJozaonii Beier (1932(, p. 182; 1933, p. 18. DINOCHEIRUS Chamberlin i42). Genotype, by original designation, also Oinoi/ieinu Chamberlin (1929a, p. 171). tommitnij nonobasic: FsfuJozaontt Beier. (Jenotype, monobasic: Dinocheirus lenodi tuJozaona Beier. Hoff (1947, p. 539). Chamberlin. Carapace lorifier than wide, with two Dinocheirus Chamberlin. Chanilierlin (1934, insverse furrows. Setae of body and palps p. 126), Hoff (1947, p. 513). )thed, usually subclavate to clavate. Dl.NCNOSls.—Carapace with two well- agellum with four setae. Palps slender, developed transverse furrows; usually no s. iSJ, .^8(7, the pedicle of the femur not eye spots. Cheliceral hand with five setae, 11 set off from the rest of the segment. the basal seta acuminate, the subbasal seta le tactile seta ist placed distad from ist subterminally denticulate; galea of male

the fixed chelal finger; st between / and commonly less branched than the galea of or a little closer to / than to sb on the the feinale; fiagellum of chelicera with four

)vable chelal finger. Legs moderately setae. Palps moderately stout ; chela of inale nder; tarsus of fourth leg without a tac- usually stouter and larger than that of the e seta. female; well-developed accessory teeth pres- This genus, which has not been reported ent on the chelal fingers; nodus ramosus

)m Illinois, can be recognized by charac- of movable finger between / and sl\ st istics given in the key. It contains the closer to / than to sb and / closer to st than tjotype, communis, from Mexico; uni- to the finger tip; ist comnKmly a little dis- 'mis (Banks), from Costa Rica; and tad from est, fig. 39B. Tarsus of fourth leg rabilis (Banks), from the eastern United with an acuminate or pseudotactile acumi- ates, where it has been taken from caves nate seta located distad from the mid-point Kentucky and Virginia. Diagnostic char- of the extensor surface and longer than the

finger of Fi^. 38. Pseudozaona mirabilis $ . A, palp, dorsal view. B, end of movable clicera; C, chela, lateral view (teeth omitted). ;

472 Illinois Natural History Survey Bulletin lol. 24, Art. 4

depth of the tarsus. Seminal receptacle of on any sternal half about 12, usually some- the female paired, very elongate, tubular, what less; setae acuminate to subacuminate with a terminal ovate sac. and paucidenticulate. Pleural membranes

Two species have been collected in Illinois. with fine wavy striations ; each stigmatic plate Several others are known from the Atlantic with one or two (rarely three) setae, some- states and from the West and Southwest. what variable; abdomen 1.65-1.8 mm. long, about two-thirds as wide as long. Key to Species CAc/iccra.—Fairly stout, deep yellow in Palpal femur with length more than 0.6 mm. ^^i^^. p^j^ ^^ ^^^^ ^j^j^ ^ f^^ ^^^^^^^

2.5 width , . , and more than times the , ^ j ^- i ^ u i .... markings; subbasal seta denticulate, basal ^eta acuminate; length of chelicera 0.24- Palpal'femur with length less than 0.6 mm. of 0.135-0.165 and less than 2.5 times the width solus 0.25 mm., width base mm., movable finger 0.2-0.23 mm. long. Fixed Dinocheirus pallidus (Banks) new finger slender; two or three small denticles combination on the inner margin of the apical tooth and

Chernes pallidus Banks (1890, p. 152). four or five denticles on the inner margin Hesperochernes pallidus (Banks). Hoff (1947, of the finger near the distal end. Movable

p. 509). finger, fig. 39C, little curved; apical tooth

Ewing (1911) listed Chelanops pallidus often weakly bicuspid ; subapical lobe weakly from Areola and from Marshall, Illinois. bicuspid or tricuspid, often a weak denticle A study of some of the specimens assigned on the finger margin near the insertion of by Ewing to this species indicates an incor- the galeal seta; gelea slender and with five rect determination, which is also evident or six acutely pointed, short rami confined when his figure (Ewing 1911, fig. 11) is to the distal one-third; galeal seta not compared with the lectotype of pallidus at reaching to the level of the tip of the galea the Museum of Comparative Zoology. serrula exterior of 17 or 18 ligulate plates. Ewing's available specimens of pallidus are Palp.—Fig. 39/^. Moderately stout; really Paracliernes squarrosus new species, granular except the face of the maxilla, the as noted under this latter species. extensor surface of the tibia and the chelal Diagnostic characters for pallidus are hand, and the fingers; setae of maxilla

given in fig. 39. The male has not been de- acuminate; setae of the trochanter and scribed previously. Three specimens of this femur subclavate and multidenticulate, those sex were taken in an Arkansas collection of the tibia multidenticulate but somewhat along with a female that agrees closely with slender and especially on the extensor sur- the lectotype at the Museum of Comparative face not subclavate; setae of the chelal hand Zoology. weakly multidenticulate to paucidenticulate, Male.—Description and measurements those of the fingers acuminate. Maxilla based on four males, one from Illinois and 0.45-0.53 mm. long, 0.27-0.32 mm. wide, three from Arkansas. Body fairly stout. Trochanter with a stout subdorsal protuber-

yellowish to light brown in color; palps ance ; length 0.38-0.45 mm., 1.4 to 1.6 times reddish-brown; body length 2.55-2.75 mm. the width. Femur with pedicle about as Carapace granular; setae clavate and fairly long as wide; extensor surface of femur numerous; anterior half of carapace weakly and somewhat flatly convex; flexor rounded, posterior portion of sides subpar- surface weakly convex except a little concave allel; posterior margin with 12 to 15 irregu- near the distal end; 0.77-0.88 mm. long, larly placed marginal setae; no eye spots; 0.27-0.31 mm. wide; length 2.75 to 3.25 carapace 0.88-0.96 mm. long, 0.6-0.8 mm. times the width. Tibia with extensor mar- posterior width a little gin somewhat flatly convex; flexor margin wide near the center ; less than the greatest width. Tergites of convex near the center but somewhat con- abdomen except the eleventh divided but first cave beyond; 0.76-0.8 mm. long, 0.29-0.34

tergite sometimes very weakly divided ; setae mm. wide; length 2.45 to 2.65 times the clavate; each first tergal scutum with 9 or 10 width. Chela as viewed from the dorsum setae, central tergal halves with as many with the extensor, flexor, and basal margins as 14 setae; tergal scuta moderately granu- more or less evenly convex; in general the lar. Sternites 4 through 10 divided, marked chelal hand is elongate-oval, tapering some- by scalelike markings; each half-sternite 4 what toward the base of the fingers, and with four setae; maximum number of setae widest in the basal half; chelal fingers —

Jmif. 1949 Hoff: Pseudoscori'ionj. or Illinois 473 slender, gently and evenly curved; chela fingers gapping when closed. Tactile setae exclusive of pedicle 1.22-1.36 mm. long, as shown in the figure. Fixed finger with a 0.43-0.52 mm. wide, length 2.6 to 3.0 times vestigial venedens and a short nonfunctional the width; chelal hand exclusive of pedicle venom duct. Marginal teeth of chelal fingers contiguous and cuspid, between 35 and 45 on each finger; each finger usually with two (occasionally only one) to four internal and six to eight external accessory teeth. Nodus ramosus of movable chelal finger

located between tactile seta / and si, usually much closer to the latter than to the former. Legs.—Legs slender; setae multidenticulate to paucidenticulate on the extensor surface of segments, paucidenticulate on the flexor surface of segments except acuminate on the flexor surface of the tarsi; femora and tibiae weakly granular or sculptured by netlike markings. First leg with trochanter 0.16-0.18 mm. long, length 1.1 to 1.13 times the width; pars basalis 0.16-0.18 mm. deep; pars tibialis 0.145-0.16 mm. deep, with both margins very weakly convex; entire femur 0.56-0.65 mm. long, length 3.1 to 3.6 times the depth; tibia slender, flexor margin weakly convex, 0.41-0.49 mm. long, 0.1-0.11 mm. deep, length 3.9 to 4.5 times the depth, length usually 4.3 or more times the depth; tarsus very slender, subcylindrical, tapering a little toward the distal end, 0.4-0.45 mm. long, 0.065-0.075 mm. deep, length 5.7 to 6.4 times the depth. Fourth leg with pars basalis 0.2-0.21 mm. deep; pars tibialis 0.23-0.24 mm. deep; entire femur with evenly convex extensor margin, flexor margin virtually straight except at the ends, 0.72-0.82 mm. long, length 3.0 to

3.4 times the depth ; tibia with weakly convex flexor margin, extensor margin nearly straight except at the basal end, 0.6-0.7 mm.

Fig. 39. Dinorlieirus paltidus i . .V, dorsal long, 0.13-0.145 mm. deep, length 4.5 to 4.9 view of palp; B, lateral view of chela; (,', times the depth; tarsus tapering a little end of movable cheliceral finger. toward the distal end, 0.45-0.50 mm. long, 0.08-0.09 mm. deep, length 5.35 to 5.75 0.64—0.69 mm. long, 0.4—0.52 mm. deep, usu- times the depth; short tactile seta on the ally 4.5 mm. or less; movable finger between extensor surface 0.32-0.37 mm. from the 0.63 and 0.72 mm. long, usually 0.7 mm. proximal end of the tarsus. or more. Viewed laterally, fig. 39B. chelal Gfii'itdl (^onipli'x.—Posterior operculum hand fairly stout, extensor and flexor mar- with about 25 setae, many of which form gins moderately convex but hand tapering an irregular marginal row, and with 6 to 8 little toward base of fingers; basal margin setae along the very posterior rim of the flatly convex, with the pedicle displaced aperture; anterior operculum very seta- somewhat toward the ventral side; movable ceous, with between 50 and 60 setae more finger markedly convex, especially near the or less scattered over the face of the oper- center; fixed finger variable, either nearly culum. straight or with the inner margin convex Female.—The two available females, one and the outer margin distinctly concave; from Illinois and one from Arkansas, are 474 Illinois Natural Ulstorv Survkv Bullktin lol. 24, .hi. 4

essentially like the male and also very simi- as in the adult except isl is wanting. Im- lar in detail to the female lectotype previ- portant measurements of the tritonyniph ously described (Hoff 1947). Some of the are given here. Body about 2.45 mm. long; minor discrepancies noticed between the carapace 0.78 mm. long, 0.58 mm. wide. present females and the lectotype can be Chelicera 0.22 mm. long, 0.13 wide; mov- attributed to the poorly preserved and able finger 0.175 mm. long. Palp with the somewhat broken condition of the lectotype. trochanter 0.32 mm. long, 0.21 mm. wide None of the differences are of sufficient value femur 0.59 mm. long, 0.225 mm. wide to justify even subspecific segregation. tibia 0.55 mm. long, 0.25 mm. wide; cheh Measurements are given to show some of exclusive of peflicle 1.03 mm. long, 0.34!

the species variations that occur. The mm. wide ; chelal hand exclusive of pedich measurement of the single available female 0.53 mm. long, 0.35 mm. deep; movable

from Illinois is followed in each instance finger 0.54 mm. long. First leg with entiri by the corresponding measurement of the femur 0.43 mm. long, depth across pan female from Arkansas. Female length 3.35 basalis 0.152 mm.; tibia 0.308 mm. long

(2.98) mm.; carapace 1.1 (1.01) mm. long, 0.087 mm. deep ; tarsus 0.34 mm. long, 0.06! 0.83 (0.675) mm. wide; abdomen about 2.3 mm. deep. Fourth leg with entire femu] long, 1.8 mm. 0.61 long, 0.192 mm. deep across thi (1.86) mm. (1.25) wide ; mm. chelicera 0.26 (0.255) mm. long, 0.155 pars tibialis; tibia 0.48 mm. long, 0.114 mm

(0.145) mm. wide across the base, movable deep ; tarsus 0.38 mm. long, 0.084 mm. deep finger 0.21 (0.21) mm. long. Palp with Distribution.—This species, originall; maxilla 0.51 (0.51) mm. long, 0.35 (0.34) described from Ithaca, New York, has bcci mm. wide; trochanter 0.51 (0.48) mm. long, taken in two collections from northern Illi 0.3 (0.32) mm. wide; femur measured along nois. In addition, three males, one female the extensor margin 0.88 (0.88) mm. long, and one tritonymph were secured by M. W greatest over-all length 0.94 (0.95) mm., Sanderson on April 13, 1940, at Lake Wed width 0.305 (0.29) mm.; tibia 0.84 (0.785) ington Wildlife Area, Washington County mm. long, 0.335 (0.315) mm. wide; chela Arkansas. exclusive of pedicle 1.44 (1.44) mm. long, The Illinois collection from Magnoli; 0.52 (0.495) mm. wide; chelal hand ex- came from a decayed log, and the Arkansa clusive of pedicle 0.75 (0.735) mm. long, specimens were taken from debris in a hoi 0.53 (0.485) mm. deep; movable finger 0.78 low tree on a wooded hillside. (0.77) mm. long. First leg with pars basalis Illinois Records.—^A single male wa 0.182 (0.178) mm. deep; pars tibialis taken in a collection made by Henry Dyba 0.155 (0.152) mm. deep; entire femur 0.65 at Palos Park, Cook County, Illinois, oi (0.625) mm. long; tibia 0.48 (0.465) mm. May 16, 1943, and a single female wa long, 0.106 (0.103) mm. deep; tarsus 0.45 taken at Magnolia, Putnam County, Illinois (0.46) mm. long, 0.068 (0.076) mm. deep. on March 23, 1944, by H. H. Ross. Fourth leg with pars basalis 0.228 (0.225) Dinocheirus solus new species mm. deep; pars tibialis 0.25 (0.246) mm. deep; entire femur 0.85 (0.83) mm. long; Specimens of Dinocheirus solus, figs. 40,^ tibia 0.68 (0.69) mm. long, 0.136 (0.133) 40B, differ from those of many species of th mm. deep; tarsus 0.49 (0.495) mm. long, genus Dinocheirus by their much smalle 0.091 (0.092) mm. deep; tactile seta 0.34 size. This new species appears to be close! (0.38) mm. from the proximal margin of related by size and general structure ti

the tarsus. (lorsalis (Banks), from which it is readil; Tritony.mph.—Very similar in most ways separated by small differences in the shap to the adult but lighter in color, much of some of the palpal segments, the lengtl smaller in size, and with some segments, and position of the tactile seta of the fourtl especially those of the legs, stouter. Mov- pedal tarsus, and numerous other details. able chelal finger with three tactile setae: Male.—Body ovate, fairly stout; yellov h (or jA?) wanting; / a little distad from to yellowish-brown in color, with the palp the 2. mid-point of the finger; st about as far a deeper golden brown ; length of body from the finger base as t is from the tip; mm. Carapace rounded anteriorly, side sb (or i?) as in the adult; nodus ramosus convex; widest across the center; furrow a little proximad from the level of tactile well marked; eyes apparently wanting; pos seta t. Fixed finger with tactile setae much tcrior carapacic margin with 12 setae; al —

ne, 1949 Hoff: Pseui>oscorpions of Illinois 475

le of carapace weakly to strongly clavate; concave distad from the center; pedicle

:s of carapace moderately granular, dor- stout ; 0.56 mm. long, 0.245 mm. wide. Chela face virtually smooth: length of carapace with outer and inner margins more or less

? mm., greatest width 0.7 mm., posterior evenly convex, the outer a little less convex th 0.66 mm. Tergites of abdomen weakly than the inner; pedicle near the center of the nular and with scalelike markings, all base; fingers slender, curved, well set off ided e.xcept the last; intertergal spaces from hand; chela, pedicle excluded, 0.9 mm. le; setae of tergites clavate and with as ny as 12 setae on some of the central ;al halves. Sternites 4 to 10 inclusive ided; fourth sternal halves each with r or five setae, central sternal halves each h 11 or 12 setae; all setae of sternites minate; sternites with scalelike sculptur- pleural membranes striated and rugose; ; lomen about 1.35 mm. long. 1.12 mm. le. llielicera.—Base fairly stout, fingers rela- •\y slender and slightly curved; subbasal

I subterminally denticulate, basal seta nnnate ; length of chelicera 0.2 mm., Ith of base 0.125 mm. Fixed finger a le curved, with five or six weakly de- nped teeth on the distal inner margin in lition to three denticles on the inner sur- e of the apical tooth. Movable finger irly straight; subapical lobe not especially

II developed; apical tooth terminally :rotic and bicuspid; galea slender and

Fig. 40. Dinodieiius solus, holotype . A, g, with live weakly developed and short i dorsal view of palp; B, lateral view of chela. niinal and subterminal rami; serrula eriiir of 17 to 18 plates; movable finger 75 mm. long. long, 031 mm. wide; chelal hand 0.495 mm. °alp. —Fig. 40/-/. Fairly stout; the lateral long, 0..?4 mm. deep; movable finger of chela face of the maxilla, the extensor surface 0.46 mm. long. From the side, hand, fig. the trochanter, and the flexor surfaces 40/J, appears somewhat quadrangular in gen- the femur and tibia coarsely to moder- eral outline; pedicle displaced far toward the ly granular; other surfaces very weakly ventral side; ventral margin weakly convex, inulate to smooth ; setae acuminate on dorsal margin more convex; fingers moder-

' maxilla; setae of the trochanter, femur. ately stout, the fixed finger nearly straight,

1 tibia somewhat stout and niultidenticu- the movable finger gently curved. Each fin- e to paucidenticulate ; setae stouter on ger with about 40 marginal teeth, conical and

' femur and the trochanter than else- with well-developed cusps at the distal end ere; chelal hand with setae chiefly pauci- of the row but rounded and acuspid at the uiculate; acuminate setae on the fingers, proximal end of the row; each finger with axilla 0..?7 mm. long, 0.27 mm. wide, five external accessory teeth; movable finger ochanter with the fle.xor, or inner margin, with three, fixed finger with two, internal derately convex; 0..32 long, 0.21 mm. accessory teeth. Nodus ramosus of movable \t. Femur moderately stout to stout, finger located just distad from the level of 6 mm. long, 0.2.?5 mm. wide; outer mar- tactile seta st. Fixed finger with a vestigial convex, more convex near the ends than venedens and a short vestigial venom duct. the center; inner margin weakly convex Legs.—Somewhat slender; yellow in the basal two-thirds but a little concave color; pars tibialis and flexor surface of tibia the distal one-third; the pedicle about as of first leg weakly granular, otherwise pedal ig as wide, well set off from the rest of segments smooth; setae of the extensor sur-

• segment. Tibia with outer margin flatly face of most segments paucidenticulate, mded, inner margin bulging, but slightly slender, not clavate; setae of the flexor sur- — —

476 Illinois Natural History Survey Bulletin I'ol. 24, Art.

face of segments chieflj' acuminate. First leg the extensor surface 0.25 mm. from tl with pars basalis 0.133 mm. deep; pars proximal margin of the tarsus. tibialis with both margins evenly convex, Genital Complex.—Posterior operculu 0.114 mm. deep; entire femur 0.43 mm. with 17 irregularly placed setae on the fa long, 0.133 mm. deep; tibia with outer mar- of the operculum and along the posteri: gin distinctly but weaicly S-shaped, flexor margin and with five setae on the posterii rim of the genital aperture; anterior ope culum with 31 irregularly placed setae, which the 4 medial ones are much long and stouter than the others. Holotype, male.—Rockford, Winnebai County, Illinois: taken from moist whe stubble, June 12, 1944, C. L. Remington.

19. HESPEROCHERNES Chamberl

Hesperoehernes Chamberlin (1924, p. 8S Genotype, monobasic: Hesperoehernes laur Chamberlin. Hesperoehernes Chamberlin. Beier (1932<:, 174). Cephalothorax clearly longer than wid carapace granular with two transverse car pacic furrows. Tergites divided, granuls Palps stout, femur with well-defined pedicl Setae of body and palps usually lightly, b clearly, clavate. Flagellum with four seta setae b and sb of hand of chelicera thickeni

and denticulate. The sensory seta ist of tl

fixed chelal finger is distad from est; st

the movable chelal finger is found near

to / than to sb. The tarsus of the four

leg is without a true sensory seta, althou;

a short-toothed pseudotactile seta may 1 present.

This is a common North American gem

and is represented by a number of speci 43 G\ from the United States, Mexico, ar Canada. H. unicolor (Banks) has been d Fig. 41. Hesperoc hemes caniidetisis (J. Dorsal view of palp. scribed from Austin, Texas. Diagnost 42. characters are illustrated in figs. 41, 42, 4 Fig. Hesperoehernes sanburni $ . Chela, lateral view (teeth omitted). 43. 20. new gem Fig. Hesperoehernes sanborni i . Tip ACUMINOCHERNES of movable finger of chclicera; galea.

setae b and sb smooth and acuminate ; 11; margin convex, 0.342 mm. long, 0.088 mm. gellum with four setae. Palps stout, seti deep; tarsus tapering very little toward the chiefly subclavate to clavate; some sexu; distal end, 0.315 mm. long, 0.061 mm. deep. dimorphism shown in palps; tactile sel

Fourth leg with pars basalis 0.14 mm. deep, St nearer to t than to sb; tactile seta / pars tibialis 0.151 mm. deep; entire femur distad from est, fig. 44Z). Fourth leg wit with flexor margin nearly straight, extensor a tactile seta distad from the mid-point ( margin flatly convex, 0.545 mm. long, 0.151 the tarsus. Seminal receptable of fema mm. deep; tibia slender, extensor margin in the form of a long slender tubule term very weakly S-shaped, flexor margin weakly nating in a closed bulb or sac. convex, 0.46 mm. long, 0.097 mm. deep; Genotype. Hesperoehernes erassopalpi tarsus subcylindrical, tapering very little to- Hoff. ward the distal end, 0.355 mm. long, 0.07 A very distinctive characteristic of th: mm. deep; a short tactile is acuminate nature of both:h seta located on genus the ^ —

urn-. 1949 Hoff: Pseudoscorpions of Illinois 477

Fi:;. 4-I. Adtminoihernis iriusopalf'iis. I, A, right leg $ ; B, right leg IV, 9 ; C, dorsal of ew palp, $ ; D, lateral view of chela, i . isal and subbasal setae of the base of the 0.26-0.3 mm. wide, length 2.0 to 2.2 times elicera. Only one species, the genotype, the width; palpal chela without pedicle 0,96- known. 1.05 ram. long. 0.425-0.49 mm. wide, length 2.14 to 2.3 times the width; chelal hand Acuminochernes crassopalpus (Hoff) 0.43-0.52 mm. deep, 0.48-0.52 mm. long new combination exclusive of pedicle ; movable chelal finger ttperoi hemes crassopalpus Hoff (19+5«, p. 0.53-0.59 mm, long. +3). Female.—The follow-ing measurements Since the present species has been de- are given as the range of six females. Body ribed in detail in a previous publication length 2.0-2.35 mm. Palps with femur 0.57- ^ofif 1945a), only measurements of the 0.62 mm. long, 0.255-0.27 mm, wide, length Ipal segments and illustrations of chela 2,2 to 2,3 times the width; tibia 0,56-0.62 id palp, figs. 44/), 44C are given here. mm. long, 0.255-0.28 mm. wide, length 2.15 he members of this species may be recog- to 2.22 times the width ; chela exclusive of zed by generic characteristics given in the pedicle 0,98-1.05 mm. long. 0.38-0,41 mm. wide, length 2.5 to 2.6 times the width; Male.—^The following pertinent measure- chelal hand e.xclusive of pedicle 0,49-0,54 ents are expressed as the limits of range mm. long, 0.375-0.425 mm. deep; movable r nine individuals. Body length 1.8-2.1 finger 0.51-0.54 mm. long. m. Palpal femur 0.5fr43.61 mm. long. Distribution.—This species, which was 265-0.295 mm. wide, length 2.0 to 2.1 previously reported only from Arkansas, has Ties the width; tibia 0.56-0.61 mm. long. been taken in eight collections in north-cen- —

478 Ili.jnois Natural History Survey Bulletin To/. 24. Art. 4

tral to southern Illinois. In addition, it characters have not been found for the accu- was taken from pack-rat nests at Lawrence, rate recognition of females of this genus. Kansas, by R. H. Beamer of the University The genus contains only the genotype. of Kansas. Mirochernes dentatus (Banks) Hesperrjchernes crassopalpiis often occurs Chelannps dentatus Banks (1895, p. 6). in great numbers in a collection, although Mirochernes dentatus (Banks). Beier (1930/7, p. on some occasions it is taken singly. Of the 216, but not pp. 217-218, fig. 14; 1932f, p. five Illinois collections bearing habitat data, 1S2). Hoff (1947, p. 502). three were secured from debris in hollow- Clierncs dentatus (Banks). Chamberlin (1931(j, trees, one was made from a decayed log, and p. 124). one came from the stomach of a red-bellied The male of this species is easily recog- woodpecker. nized by the toothlike projection on the chelal Illinois Records. Cache: April 19, hand, fig. 45C From related Illinois pseudo-

1944, Ross & Sanderson, 4 15 Eogewood: scorpions the females may be differentiated grass pile, July 25, 1947, Sanderson & Stan- by characters given in the key. The female nard, 79, 10^. Gillespie: Aug. 30, 1944, is described here in considerable detail, since,

Clarence & Marie Goodnight, 1 9 . Herrin : up to the present time, this sex has been July 8, 1944, W. Snow, 1 tritonymph (ws). undescribed. The females of this species ap- Lawrence: Aug. 25, 1944, W. Snow, 1 pear to be much more abundant than the specimen. Magnolia: March 23, 1944, males. In some collections, usually mixed of Ross, great numbers i i , 9 9, and with specimens of other species, are nymphs nymphs. Thom.asboro: in corn mash, Nov. probably of this species. However, since it

10, 1947, Cooper, 19, 5 immatures. is impossible to state with certainty that the Urbana: Nov. 12, 1934, A. C. Toumev, 1 9 nymphs are of dentatus, they are not de- (HJV). scribed here. Female.—Measurements given represent 21. MIROCHERNES Beier the range of eight females. Body and legs

Mirocherncs Beier (1920*, p. 216; 1932f, p. light brown in color; palps dark reddish- 182). Genotype, by original designation and brown; legs moderately slender, palps stout; monobasic: Chctanops dentatus Banks. body fairly stout, 2.2-3.15 mm. long. Cara- Diagnosis.—Chelicera with flagellum of pace darker and more red in color than the four setae; seta b of base of chelicera abdomen; transverse furrows well marked; acuminate, seta sb denticulate ; usually tv\ o no eye spots; anterior portion of carapace acute denticles on the inner margin of the rounded, sides convex; greatest width near movable finger near the level of the inser- the center, slightly narrower across the pos- tion of the galeal seta. Palps stout, the terior margin; surface moderately to chela of the male with an internal hooklike coarsely granular; setae distinctly clavate, ornament on the hand, fig. 45C; sexual usually 12 setae along the posterior carapacic dimorphism marked in the palps; setae sub- margin; carapace 0.82-0.99 mm. long, great- clavate to clavate ; tactile seta st nearer to est width 0.67-0.85 mm., posterior width

/ than to sb ; tactile seta ist distad from est, 0.64—0.82 mm. Abdomen ovate in general fig. 45/^. Fourth leg with tactile seta dis- outline; tergites except the eleventh divided; tad from the mid-point of the tarsus. Female interscutal spaces mostly wide and conspicu- with seminal receptacle consisting of a long ously granulate ; each first half-tergite with tubule with a saclike bulb at the end. six or seven setae; central tergal halves with The generic diagnosis has been amended as many as 10 setae, all clavate; surface of above to include the tactile seta on the tarsus tergal scuta weakly to moderately granular. of the fourth leg. Previously, the tactile Sternites very weakly sculptured, sternites seta was reported as wanting (Beier 1932f, 4 through 10 divided; each fourth half-ster- Hoff 1947). The tactile seta apparently had nite with three or four setae, central tergal been broken from the fourth pedal tarsus of halves with as many as 14 setae, all acumi- the male lectotype previously examined by nate ; interscutal spaces wide and very weakly the present writer (Hoff 1947) and its pres- sculptured, striate to granulate. Each an- ence was, as a result, not reported. terior stigmatic plate with three setae, each Males of this genus are easily recognized posterior plate with one; pleural membranes by the unusual modification of the inner sur- very rugose and papillose; abdomen 1.4—2.2 face of the chelal hand. At the present time mm. long, greatest width 1.05-1.6 mm.

J — ; ;

June. 1949 Hoff: Pseudoscorpions of Illinois 479

Fig. 45. Mirochernes Jentalus. A, l.Tteral view of chela, $ ; B, dorsal view of palp, 9 cheliceral finger, C, dorsal view of chela, i ; D, tip of movable 9.

Chelicera.—Fairly stout, yellow in color illa and most of the chela virtually smooth; exterior aspect of base of hand sculptured setae of maxilla acuminate, setae of the with nctlike markings; subbasal seta termi- trochanter and femur subclavate, setae of nally and subterminaliy denticulate, basal the flexor surface of the tibia and chelal seta acuminate; chelicera between 0.25 and hand multidenticulate while those of the ex- 0.3 mm. long, width of base 0.145-0.17 mm., tensor surface of the tibia and chelal hand length of movable finger 0.21-0.25 mm. are paucidenticulate ; setae of the fingers Fi.xed finger with three denticles on the inner acuminate. Maxilla 0.43-0.51 mm. long, surface of the apical tooth and usually two 0.27-0.35 mm. wide, length 1.4 to 1.6 times large and three small denticles on the inner the width. Trochanter stout, with two well- finger margin; lamina exterior well de- rounded protuberances; 0.435-0.51 mm. veloped and extended as a keel along the long, 0.24-0.3 mm. wide, length 1.65 to 1.82 base of the chelicera; all except the distal times the width. Femur with a cylindrical four plates of the serrula interior fused into pedicle, about as long as wide; femur en- a velum. Movable finger, fig. 45D, only a larged suddenly beyond the pedicle and little curved; subapical lobe large; one or slightly narrowed toward the distal end; two acute but small denticles present on the extensor margin flatly convex in the central inner fmger margin near the level of the portion; flexor margin slightly S-shaped insertion of the galeal seta; serrula exterior femur widest near the center; femur along of 18 to ly plates; galeal seta reaching only the extensor margin 0.6-0.75 mm. long, about half way to the tip of the galea; galea 0.26-0.325 mm. wide, length 2.27 to 2.34 with usually six terminal and lateral rami, times the width. Tibia with pedicle larger all simple and arranged along little more than that of the femur and about as long than the terminal one-half of the galea. as wide ; flexor margin rounded and bulg- Palp.—Fig. 45B. Surface moderately ing except flattened or a little concave near granular on trochanter and femur, tibia the distal end; extensor margin flatly con- weakly granular except smooth on the ex- vex except in the terminal one-third; 0.61- tensor surface, the ventral face of the max- 0.8 mm. long, 0.27-0.34 mm. wide, length ;

480 Illinois Natural History Sur\ev Bulletin I'ol. 24, Art,

2.17 to 2.4.? times the width. Chela with 0.076-0.088 mm. deep, length 5.5 to 6, h;ind stout, fingers slender and gently times the depth; tactile seta present curved; both extensor and flexor margins tarsus and located about two-thirds of t of chi-lal hand convex, the flexor much more segment length from the proximal marj so than the extensor; hand tapering rapidly of the segment, seta short and easily broki toward the fingers; pedicle displaced toward Genital Complex.—Usually about 10 sel the e.\tcnsor side of the hand ; chela exclusive along the posterior margin of the posteri of pedicle 1.07-1..33 long, 0.365-0.465 mm. operculum and 18 to 22 setae scattered wide, length 2.6 to 3.0 times the width; the anterior operculum. Seminal recepta chelal hand exclusive of pedicle 0.48-0.6 with surface of bulb at end of tubule rug( mm. long, 0.38-0.475 mm. deep; movable or wrinkled. chelal linger 0.625-0.78 mm. long. From the Male.—Description based on two Illin side, chelal hand, fig. A5A. appears stout; males; the measurements of one are giv pedicle displaced far toward the ventral side; in parentheses following the correspond] fixed finger nearly straight, movable finger measurements of the other. Body, appcr teeth of ages, and most details as in the female. usually a little curved. Marginal . T chelal fingers conical, contiguous, and with chela, fig. 45C, is much stouter than in t well-defined cusps; usually 50 to 60 marginal female and bears a hooklike appendage teeth on each finger, with slightly more on the subflexor surface. Body length 2.3 (2. the fixed than on the movable finger; acces- mm.; carapace 0.97 (0.88) mm. long, sory teeth variable, usually two to four (0.77) mm. wide; cheliceral finger 0, internal accessory teeth and six to eight ex- (0.24) mm. long. Palp with maxilla I ternal accessory teeth. Nodus ramosus of (0.49) mm. long, 0.35 (0.33) mm. wit movable finger usually very near the level trochanter about 0.5 mm. long and 0.3 m of tactile seta st. Tactile setae of chelal wide; femur 0.8 (0.75) mm. long, 0, fingers as shown in the figure. (0.325) mm. wide; tibia 0.83 (0.76) m Legs.—Yellow in color; setae of the flexor long, 0.365 (0.33) mm. wide; chela exc surface of segments (except pars tibialis of sive of pedicle 1.38 (1.32) mm. long, wic fourth leg) chiefly acuminate, fairly long exclusive of hook 0.525 (0.51) mm.; che and numerous; setae of the extensor sur- hand exclusive of pedicle 0.67 (0.65) m face multidenticulate to paucidenticulate long, 0.56 (0.54) mm. deep; movable che surface of segments smooth except very finger 0.75 (0.77) mm. long. First leg w weakly granular on the femoral parts of the pars basalis 0.212 (0.178) mm. deep; p: fourth leg and sometimes on the femur of tibialis 0.17 (0.145) mm. deep; entire fem the first leg. First leg with pars basalis 0.63 (0.57) mm. long; tibia 0.465 (0.4 0.16-0.197 mm. deep; pars tibialis slender, mm. long, 0.118 (0.106) mm. deep; tars extensor margin weakly curved, flexor mar- 0.45 (0.41) mm. long, 0.076 (0.071) m gin nearly straight to very weakly curved, deep. Fourth leg with pars basalis 0. 0.129-0.155 mm. deep; entire femur 0.48- (0.194) mm. deep, pars tibialis 0.24 (0.21 0.61 mm. long, length 2.98 to 3.28 times the mm. deep; femur 0.78 (0.73) mm. lor depth; tibia very weakly S-shaped, 0.36-0.46 tibia 0.64 (0.59) mm. long, 0.145 (0.13 mm. long, 0.093-0.114 mm. deep, length 3.85 mm. deep; tarsus 0.53 (0.48) mm. loi to 4.2 times the depth; tarsus very slender, 0.092 (0.09) mm. deep; tactile seta prese tapering a little toward the distal end, 0.37- on tarsus as in the female. 0.45 mm. long, 0.06-0.072 mm. deep, length Genital Complex.—Between 20 and 5.6 to 6.6 times the depth. Fourth leg with setae on the posterior operculum with 4 pars basalis 0.175-0.212 mm. deep; pars 6 smaller setae on the very posterior r tibialis 0.188-0.225 mm. deep; entire femur of the genital aperture; nearly 30 scatter somewhat slender, extensor margin evenly setae on the anterior operculum. but not strongly convex, flexor margin nearly Distribution.—This widespread easte straight, 0.63-0.8 mm. long, length 3.26 to species, originally described from Floric

3.55 times the depth ; tibia S-shaped with has been collected from nine localities the extensor margin markedly concave in Illinois, ranging from the central to t the distal two-thirds, 0.5-0.645 mm. long, southern part of the state. 0.114-0.133 mm. deep, length 4.35 to 4.85 Two collections were taken from fun times the depth; tarsus tapering a little one from a rotten log, three from tree hoi toward the distal end, 0.43-0.53 mm. long, three from ground cover and woody debt

I — — ;

7. 24. An. 4 Hoff: Pseudoscorpions of Illinois 481

o from mammal nests, ami one trum the 46/i, bearing long clavate setae; tactile seta imach of a reil-bellieii woodpecker. si of movable chelal finger closer to / than Illinois Records. Cache: debris in liol- to sb; ist considerably distad from est on V tree, April 19. 1944, Ross & Sanderson, fixed chelal finger; both ib and isb distad >. Cahokia: "50" on cork, Aug. 6, 194.<, from the level of esb; palps showing little

. Snow, 19 (ws). H.'WANA: debris and sexual dimorphism. Tarsus of fourth leg

St in log. Nov. 9, 1943, Ross & Sanderson. without a tactile seta. Seminal receptacle

} ground cover below levee near river, of female not observed. ;

3V. 9, 194.^ Ross & Sanderson, 1 9 . Genotype. lUiniihernis ilistinctus new

ERRIN : July 24, 1944, W. Snow, 1 9 (ws). species. vmpsville: leafy and woody debris on hill- This genus appears closely related to the le, Sept. 30, 1943, Ross & Sanderson, 1 i . genus Hesperocheriits Chamberlin, from

Narca: fungus in tree hole, July 22, 1943, which it may be separated without difficulty

. H. Ross, 29. Quincy: near Burton's by the nature of the setae of the body and ive, mouse nest and dead wood in hollow palps and the acuminate condition of the ag. April 27, 1944, C. Hoff, \$ (ch). basal seta of the cheliceral hand. Only one

*bana: in rotten log, March 29, 1942, H. species is known in the genus.

. Ross, 1 9 ; tree hole, .Nov. 12, 1944, W. Illiiiichernes distinclus new species ow. 1 9 (ws) ; University Woods, stom- tl of red-bellied woodpecker, Nov. 12-13, This species is the only one kno«n in the

34, A. C. Touniey, 1 9 (hjv). White genus; hence, the diagnostic features of the

EATH : "ex-fungi," Aug. 5, 1939, Ross & genus are also the diagnostic features of the egel, 2 9 . species. Several diagnostic structures are

illustrated in fig. 46.

22. ILLINICHERNES new genus Male.—Description based on three males, including the holotype. Measurements are Dlagnosis.—C'helicera with flagellum of given as the limits of range. Body stout ur setae; basal seta of cheliceral hand palps and legs moderately stout; body and uminate, subbasal seta denticulate. Palps legs light brown; palps deep reddish-brown irly stout ; setae, figs. 46C-46£, of palps or golden in color; body 1.7-1.85 mm. long. d more especially of dorsum of body bi- Carapace with anterior half rounded, later- terally feathered, leaf like, and stout; al margins convex; surface coarsely granu- tae of sternal scuta chiefly clavate; prox- lar; setae stout, wide, and feather-like in lal two-thirds of fixed chelal finger, fig. general appearance; no eye spots; median

Fig. A6.—lllinir/i,rnrs distinctiis, holotype i. A, dorsal view of palp; li, lateral view chela; C, a seta of the palpal femur; D, another seta of the palpal femur; E, side view of a la from the palpal femur. 482 Illinois Natural Histoky Survey Bulletin Jol. 24, Art.

transverse furrow a little posteriad to or ticulations; setae of trochanter, femur, tibij near the center of the carapace, posterior and chelal hand clavate, stout, very simila furrow much nearer to the posterior cara- to those of the carapace and tergites; fixei pacic margin than to the median furrow; finger with long clavate setae on the dorsa 12 to 14 setae along the posterior margin and extensor surfaces of more than the basa

uf the carapace ; length of carapace 0.65-0.72 one-half of the finger, setae of the remain mm., greatest width near the center and der of the fixed finger and the entire mov

equal to 0.62-0.65 mm. ; posterior width able finger acuminate. Maxilla 0.33-0.3 very slightly less than the greatest width. mm. long, 0.25-0.26 mm. wide. Trochante Abdomen oval, very stout; tergites except with well-defined pedicle about as long a the eleventh divided; surface of tergites wide; subspherical in shape beyond th granular; interscutal spaces not especially pedicle; sublateral and subdorsal protuber

wide, usually narrow ; each scutum of ances rounded and not much elevated first tergite with six to eight setae; maxi- thickly set with setae on the flexor surfac mum number of setae on any tergite is about but very few setae on the extensor surface 11; all tergal setae stout and clavate, like trochanter 0.32-0.385 mm. long, about 0.21 those of the carapace. Sternites 4 to 10 0.242 mm. wide, length 1.5 to 1.6 times th divided, interscutal spaces narrow and stri- width. Femur with a well-defined pedicl ate; setae of sternal halves varying from about as long as wide; femur subcylindrica subacuminate on the anterior part of the beyond the pedicle except near the dista abdomen to strongly clavate on the central end; extensor margin flatly convex in th and posterior portions; each fourth sternal central part, a little more convex beyond scutum with 5 or 6 setae, maximum num- flexor margin very weakly convex in th ber on central sternites about 10; surface of central part and very weakly concave in th sternal scuta with scalelike markings. Each distal one-third or one-fourth; 0.6-0.69 mm anterior stigmatic plate with two or three long, 0.21-0.225 mm. wide, length 2.85 t small acuminate setae, each posterior plate 3.05 times the width. Tibia pedicellate with three. Pleural membranes very rugose extensor margin flatly convex in the centra and irregularly striate; length of abdomen part but a little more convex near each end 1.05-1.13 mm., width about 0.95-1.02 mm. flexor margin centrally rounded and some Chelicera.—Yellow in color; fairly stout; what bulging, flattened or very little concav exterior surface of base marked by weakly in the distal part; tibia 0.57-0.63 mm. long developed netlike lines; subbasal seta with 0.225-0.25 mm. wide, length 2.5 to 2.5 three or four terminal and subterminal spi- times the width. Chela with both extenso nules; basal seta smaller and acuminate; and flexor margins of hand gently am largest flagellar seta unilaterally serrate evenly rounded; pedicle placed slightly to along the distal half; the two smaller flagel- ward the extensor margin; fingers relativel; lar setae subequal in length; chelicera about stout, slightly curved, and tapering gradu

0.19 mm. long and with the base 0.12 mm. ally toward the distal end ; chela exclusiv wide; length of movable finger between 0.145 of pedicle 0.84-0.955 mm. long, 0.34-0.36 and 0.165 mm. Fixed finger slender; three mm. wide, length 2.45 to 2.6 times th'

small rounded teeth on the inner surface of v.'idth ; chelal hand without pedicle 0.44- the apical tooth followed by four (of which 0.49 mm. long, 0.32-0.375 mm. deep; lengtl the basal two are weak) denticles along the of movable chelal finger 0.42-0.48 mm inner finger margin. Movable finger with From the side, chela, fig. 465, fairly stout a long and slender apical tooth, subapical pedicle displaced conspicuously toward thi lobe moderately well developed but much ventral side; ventral margin a little les shorter than the apical tooth ; galeal seta convex than the dorsal margin; fixed finge: reaching about to the level of the tip of stout and straight, tapering regularly to the galea; galea straight and with two or ward the distal end; movable finger curvec three very minute denticles (often not dis- and more slender than the opposing finger cernible) confined to the distal one-third Movable finger with nodus ramosus betweei of the galea; serrula exterior consisting of one and two areolar diameters basad fron 15 or 16 ligulate plates. the level of tactile seta st. Tactile setai Falp.—Fig. 46^. Coarsely granular ex- placed as shown in the figure. Margina cept on the chelal fingers; most setae of teeth of chelal fingers contiguous, and, eX' maxilla weakly clavate, with numerous den- cept for a few proximal teeth, cusp-bearing ;

««,-, 1949 HoFF: PSEUDOSCORPIONS OF ILLINOIS 483

between 30 35 marginal teeth in sually and the male ; galeal seta not extending to n each finger; movable finger usually with the tip of the galea; serrula exterior of 16 3ur or five external and one or two internal to 17 plates; chelicera 0.21-0.22 mm. long, ccessory teeth ; fixed finger with seven or base 0.112-0.117 mm. wide, movable finger ight external and two or three internal 0.15-0.155 mm. long. ccessory teeth. Vestigial venedens and I'alfi.—X'irtually like that of the male. dort venom duct on fixed finger. Maxilla 0.35-0.38 mm. long, 0.24-0.26 mm. Legs.—Moderately slender; most seg- wide, length 1.43 to 1.48 times the width; lents except the tarsi sculptured by scale- trochanter 0.36-0.39 mm. long, 0.22-0.24 ke to granular markings; all setae except mm. wide, length 1.58 to 1.6 times the few on the distal portion of the tarsi width; femur measured along the extensor lultidenticulate and clavate to subclavate. margin 0.64-0.73 mm. long, 0.21-0.225 mm. irst leg with pars basalis 0.13-0.14 mm. wide, length 2.97 to 3.22 times the width; tibialis tibia eep ; pars slender, extensor margin 0.58-0.66 mm. long, 0.225-0.25 mm. little convex, flexor margin less convex to wide, length 2.43 to 2.64 times the width Imost straight. 0.11-0.12 mm. deep; entire chela exclusive of pedicle 0.88-0.975 mm. ;mur 0.42-0.47 mm. long, length 3.2 to long, 0.325-0.37 mm. wide, length 2.55 to

.35 times the depth ; tibia with flexor mar- 2.7 times the width; hand of chela without in a little convex, extensor margin very pedicle 0.45-0.5 mm. long, 0.325-0.37 mm. eakly concave in the distal two-thirds, deep; movable chelal finger 0.45-0.51 mm. .32-6.35 mm. long, 0.08-0.086 mm. deep, in length. Tactile setae and teeth of chelal ;ngth 3.95 to 4.1 times the depth; tarsus fingers as in the male. ith the extensor margin almost straight, Legs.—As in the male. First leg with pars exor margin a little convex, tapering some- basalis 0.133-0.143 mm. deep; pars tibialis hat toward the distal end, 0.34—0.38 mm. 0.11-0.12 mm. deep; entire femur 0.44—0.51 jng. 0.058-0.064 mm. deep, length 5.85 to mm. long, length 3.22 to 3.6 times the depth .4 times the depth. Fourth leg with the tibia 0.34-0.38 mm. long. 0.085-0.09 mm. ars basalis 0.135-0.148 mm. deep; pars deep, length 3.92 to 4.22 times the depth Ibialis 0.145-0.159 mm. deep; entire femur tarsus 0.35-0.38 mm. long, 0.065-0.07 mm. airly slender, extensor margin evenly con- deep, length 5.0 to 5.6 times the depth. ex, flexor margin nearly straight, 0.51- Fourth leg with pars basalis 0.137-0.152 .595 mm. long, length 3.45 to 3.8 times mm. deep; pars tibialis 0.145-0.158 mm. be depth ; tibia weakly S-shaped. 0.43-0.48 deep; entire femur 0.56-0.64 mm. long, 3.65 im. long. 0.09-0.1 mm. deep, length 4.6 to 4.05 times the depth; tibia 0.45-0.51 mm. 3 4.9 times the depth; tarsus with both long, 0.092-0.103 mm. deep, length 4.65 to margins slightly convex, tapering in the dis- 4.95 times the depth; tibia 0.39-0.42 mm. il one-half, 0.37-0.4 mm. long, 0.07-0.072 long, 0.069-0.076 mm. deep, length 5.3 to 5.8 im. deep, length 5.3 to 5.6 times the depth. times the depth. Genital Complex.—Anterior operculum Genital Complex.—Anterior operculum lith usually between 35 and 40 acuminate with 30 to 35 scattered setae; posterior nd well-developed setae; posterior oper- operculum with 13 to 15 setae arranged in ulum with four to six multidenticulate a single marginal row along the posterior etae along the posterior margin, with a margin of the operculum. Dtal of about 20 setae on the operculum. Tritonv.mph.—Observations and meas- Fem.ale.—Measurements and ratios given urements based on three individuals. Body re the ranges of three females, the allo- and appendages with color, sculpturing, and tpe and two paratypes. Essentially like chaetotaxy much as in the adult; body 1.25- he male; body 1.95-2.05 mm. in length. 1.45 mm. long. Carapace usually with 10 to arapace with 14 to 16 marginal setae, 12 setae along the posterior carapacic mar- .72-0.79 mm. long, greatest width 0.61- gin; carapace about 0.6 mm. long, 0.52 mm. .69 mm., posterior width little less than wide. Tergites less sclerotic than in the he greatest width. Abdomen 1.1.5-1.3 mm. adult; each first tergal scutum with five or :)ng, 1.05-1.2 mm. wide. six setae, central scuta with no more than Chelicera.—Chiefly as in the male except eight setae. Sternites faintly sculptured, he galea with five terminal and subterminal without color, weakly sclerotized ; setae ami, each minute and simple, but much as in the adult, four or five setae on each nore highly developed and conspicuous than fourth half-sternite, central sternal halves — ;

484 Illinois Natural History Survey Bulletin Jol. 24, Art. 4

with no more than six setae. Each stigmatic gin virtually straight to a little concave in plate with two setae ; abdomen 0.69-0.84 the distal two-thirds; the tarsus tapering mm. long, 0.72-0.77 mm. wide. markedly in the distal one-half; pars tibialis Chelicera.—Like that of the female in all 0.114—0.122 mm. deep; entire femur 0.41- details including the nature of the galea, 0.42 mm. long, length 3.45 to 3.6 times the but smaller and less sclerotic. Chelicera depth; tibia 0.32-0.33 mm. long, 0.08-0.085 0.175-0.19 mm. long, base about 0.1 mm. mm. deep, length 3.8 to 4. 15 times the depth wide; movable finger 0.13-0.135 mm. long; tarsus 0.29-0.31 mm. long, 0.064-0.065 mm. scrrula exterior of 14 ligulate plates. deep, length 4.55 to 4.8 times the depth. Palp.—Essentially like that of the male Protonymph.—Description based on two except the segments are smaller; the femur individuals; measurements of one are given and tibia, especially the pedicles, are rela- in parentheses after the measurements of tively stouter while the chela is a little more the other whenever the two difter. Body slender; the palps are a little lighter in color stout; lighter in color than the adult; length than in the male. Palps with maxilla 0.27- 1.02 (0.94) mm. Setae of body, legs, and 0.29 mm. long, 0.185-0.2 mm. wide, length palps like those of the adult except much about 1.45 times the width; trochanter less numerous. Ten or 11 plates on the about 0.285 mm. long, 0.17-0.18 mm. wide; serrula exterior of the movable cheliceral femur measured along the extensor margin finger. Palps much lighter in color than in 0.45-0.47 mm. long, 0.16-0.17 mm. wide, the adult; surface of trochanter and femur length 2.75 to 2.85 times the width; tibia granular, surfaces of tibia and chela slightly 0.42-0.45 mm. long, 0.175-0.185 mm. wide, granulate or smooth; clavate setae on the length 2.4 to 2.45 times the width; chela side of the fixed chelal finger as in the adult. exclusive of pedicle 0.66-0.68 mm. long, Palpal segments smaller and, with the ex- 0.245-0.25 mm. wide, length between 2.65 ception of the chela, much stouter than in and 2.8 times the width; chelal hand with- the tritonymph. Palpal femur 0.2 (0.21) out pedicle 0.33-0.34 mm. long, 0.24 mm. mm. long, 0.095 mm. wide ; tibia 0.2 mm. deep; movable finger 0.34—0.35 mm. long. long, 0.105 (0.1) mm. wide; chela 0.39 From the side, the chelal hand appears less (0.40) mm. long exclusive of pedicle, about stout than that in the adult. Movable 0.135 mm. wide; chela 0.135 mm. deep: finger with three tactile setae: t about one- hand exclusive of pedicle 0.2 (0.19) mm. third of the finger length from the tip; st long; movable finger 0.205 mm. long. Each in the basal half of the finger and very little chelal finger with between 15 and 20 mar-

closer to 1 than to sb; sb between one-fourth ginal teeth, chiefly acuspid ; no accessory teeth and one-fifth of the finger length from the observed. Movable finger with one tactile hand margin; b wanting; nodus ramosus seta {tf) near the center of the finger.

about midway between / and st. Fixed Three setae on the fixed finger ; two are finger with tactile setae much as in the external, one about one-third of the finger

adult except seta ist is wanting. About 25 length from the tip and the other near the

or 30 marginal teeth on each finger; some- base; one is internal, located between one- what fewer accessory teeth than in the adult. third of the finger length from the base and Legs.—Lighter in color, somewhat less the mid-point of the finger. sclerotic, smaller, and a little stouter than Holotype, male.—Magnolia, Illinois: in the adult; surface of segments virtually decayed log, March 23, 1944, H. H. Ross. without sculpturing; setae as in the adult. Allotype, female.—Same data as for First leg with segments shaped much as in holotype.

the adult except that the tibia and the tarsus Paratype. Illinois.—Kell: March 7,

are much stouter and the tarsus narrows 1945, Ross & Sanderson, 2

more rapidly toward the distal end; entire 1 tritonymph. Magnolia: same data as for femur 0.33-0.35 mm. long, length 3.1 to holotype, 2 9,3 tritonymphs, 1 9 (ch). 3.2 times the depth; tibia 0.24 mm. long, No habitat data accompany the Kell col- 0.072-0.076 mm. deep, length 3.15 to 3.35 lection. times the depth; tarsus 0.26-0.28 mm. long, 23. Genus? corticis Ewing 0.06-0.061 mm. deep, length 4.35 to 4.7 times the depth. Fourth leg much like that Chelanops corticis Ewing (19U, p. 75). of the male; the flexor margin of the tibia In spite of the large number of collections

evenly but weakly convex, the extensor mar- available, I have been unable to associate June. 1949 HoFF: PSEUDOSCORPION'S OF ILLINOIS 485

any of the Illinois specimens with Chelanops mined nymphs are from Champaign, Mason, corlicis described by Ewing. Since Ewing's Iroquois, Vermilion, St. Clair, Alexander, description does not include generic key Will. Jackson, Calhoun, Lake, Madison, characters in use at present, and since it has and Kane counties. been impossible to locate the types of this species, I am unable to assign corticis even ATEMNIDAE tentatively to a genus. According to corre-

spondence from J. C Chamberlin, the species Members of this family are rare in the should serve as the genotype of a new genus. \Vestern Hemisphere, being typically Ori- However, since no specimens are available ental and Ethiopian in distribution, (^ne

for study, I hesitate to establish a new genus species, Paratemnus elongatus (Banks), is with corticis as the genotype. known from Florida.

From Ewing's description, it is apparent that the species belongs in the family Cher- CHELIFERIDAE netidae and the subfamily Chernetinae.

On the basis of Ewing's description, it is Pseudoscorpions belonging in this family possible to devise means of separating corticis may be recognized by the absence of acces- from other species of the subfamily Cher- sory teeth from the chelal fingers and by netinae found in Illinois. Among the im- the presence of a venom apparatus and tooth portant characteristics listed for corticis in on each of the chelal fingers, fig. 51C. The

the original description and not found in world fauna of the family is divided into other Illinois species are the following: three subfamilies. One of these, fig. 47, the 1. Galea very long, about two-thirds as Cheliferinae, is present in the central and long as the movable cheliceral finger. eastern part of the United States. Another

2. The flexor margin of the palpal femur subfamily, the Withiinae, is represented in is bulging just distad from the pedicle: then the fauna of America north of Mexico only is virtually straight for at least two-thirds by a few species, restricted as far as known of the length of the femur. to Texas and California. i. The flexor margin of the palpal tibia KeV to SlBFAMII.lES is markedly bulging in the basal half; then Flagellum with tour or live setae; usually some is virtually straight beyond ; while the other abdominal sternites of the males with clusters margin beyond the pedicle is more or less of microsetae; coxae o\ male without coxal evenly rounded.

sacs; well-developed genital sacs lacking- . . . 4. The palpal hand is suboval in general Withiinae shape and the palpal fingers are much stouter Flagellum with three setae; male without than in most species of Chernetinae. clusters ot microsetae on abdominal ster- 5. The hairs of the fingers arise from nites; coxal sac present in the fourth coxa; minute tubercles. well-developed genital sacs usually present, Illinois Records.— In the original de- fig. 10 Ciieliferinae scription two collections are cited, both from Illinois, as follows: Havax.'^: from under Subfamily WITHIINAE

bark of trees standing in water, Aug. 9, 1908, H. E. Ewing. 2 specimens; Urb.axa: The subfamily is represented in the United States by only one genus, which has been March, 1902, J. W. Folsom, 2 specimens. reported from the southern part of the UNIDENTIFIED NYMPHS L nited States and from the West Coast region.

Among the many collections examined, a few contained chernetid nymphs unassoci- Subfamily CHELIFERINAE atcd with adults or nymphs that are obvi- The subfamily is characterized above in ously of different species from the adults in the key. Two tribes are described in the the same collection. In these instances where subfamily, both represented in Illinois. certain association cannot be made between the immature and adult animals, it seems Key to Genera advisable to refrain both from describing 1. Dorsal plates ot the entire posterior half the nymphs and from giving tentative identi- ot the abdomen bearing a seta in the fications. Collections containing undeter- center of each of the sclerotized halves, —

Survey Bulletin Vol. 24. Art. 4 486 Illinois Natural History

of leg peripheral Tibia \]4 times as long as the tarsus fig. 51fi, in addition to the IV; coxae IV of males with spurs near setae ."' anterolateral corner Dorsal plates of the posterior portion of the 25. Idiochelifer the abdomen having only peripheral setae on each of the sclerotized halves, Tribe GHELIFERINI

that In this tribe the male has coxal sacs lack well-differentiated atria and the statumen convolutum of the genital complex is invaginated anteriorly to form a median depression in which lies a sclerotic rod. The female, almost without exception, has the median cribriform plates paired and separate, not fused together. About a dozen genera have been placed in from this tribe of which eight are known the nearctic and neotropical regions and three from Illinois. A key to all the genera

in the tribe is given by Hoff (1946(f).

24. CHELIFER Geoffroy

Chelifcr Geoflfroy (1762, p. 617). Genotype, by subsequent designation of Simon (1879): Acarus canrroides Linnaeus. Chelifer Geoffrey. Chamberlin (1932, p. 19), Beier (1932'.-, p. 235). Diagnosis.—Cephalothorax and palps granular; cephalothorax with numerous large granules scattered among the others; An ex- Pig. 47. Dactylochelifer copiosus. eyes present; tergites divided, anterior ter- Monosphyronida and ample of the suborder gites of the male with lateral keels. Flagel- the family Cheliferidae. lum with subbasal seta of the base absent. Palp slender. Tarsus of the first pair of legs on last one or two spine; sub- except occasionally in the male without terminal 3 segments, fig. SOB terminal setae of fourth pedal tarsus den- III 2. Tarsal claws of at least legs II and modi- ticulate; tarsal claws bifid except for distally split or having a small to med- fied claws of first leg of male. ium subterminal inner tooth, as in fig. single species occurs in North America. 50D, but larger; plumose setae of the A carapace arising from greatly enlarged (Linnaeus) tubercles or warts; statumen convolutum Chelifer cancroides male genitalia invaginated ante- of the Acarus cancroides Linnaeus (1758, p. 616). containing a median sclerotized riorly, Chelifer cancroides Fourcroy (1785, p. 526). within the invagination; fourth 63). rod Chelifer muricatus Say, In part (1821, p. coxal male genital sac without a difl^er- Chelifer cancroides dentatus Ewing (1911, p. entiated median atrium. 73). 24. Chelifer (1932f, Chelifer cancroides (Linnaeus). Beier Tarsal claws of all of the legs without p. 236), Hoff (1944a, p. 123). lateral or inner teeth; plumose setae Inasmuch as cancroides is the only known of the carapace not arising from con- the genus Chelifer, it can spicuously enlarged warts; statumen Illinois species of the generic convolutum of the male genitalia round- be identified on the basis of ed anteriorly, not cleft, and without a characteristics, figs. 9, 48. Measurements fig. fourth given below median sclerotized rod, 10; of several Illinois individuals are male genital sac having a well- the palpal coxal to show the variation that occurs in atrium medially, fig. 10 marked segments. 27. Dactylochelifer Through the kindness of Henry Dietrich subequal in 3. Tibia and tarsus of leg IV have of the Cornell University Museum, I length; coxae without spurs the type collection of 25. Paisochelifer examined six males of —

une. 1949 Hoff: Pseudoscorpions of Illinois 487

Ihelifer cancroides dentatiis Ewing from molest man only infrequently, one collection 3tto, New York. All of these were found was labeled "Attacking People." o be typical cancroiilcs. The species is much more common than Several nymphs, apparently of this species, the number of collections reported here vere found in some of the collections. These would indicate because most of the collec- lymphs differ markedly from the adults by tions used in this study were taken from laving entire and not toothed tarsal claws natural habitats. Most of the pseudoscor- )n the legs. A description of the nymphal pions brought to schools and museums for itages is postponed until a larger number identification are of this species; people ordi-

)f specimens can be secured for study. niarily do not encounter the species that occur in soil, under the bark of trees, and in other natural habitats. Ewing (1911) recorded cancroides and

its varieties from several localities in Illi- nois. Several of these records apply to other species, but the record of one specimen from a house in Areola is probably true cancroides. Illinois Records.—Many specimens of both sexes have been collected from Areola, Champaign, Chicago, Ueerficld, Freeburg, CJlencoe, Palos Park, Quincy, Roodhouse, Shumway, Springfield, Urbana, Waukegan.

Fig. 48. Chelijir lancrouies 9 • Dorsal riew of palp. 25. IDIOCHELIFER Chamberlin

Idiochelijer Chamberlin (1932, p. 19). Cleiio- Male.—Measurements and ratios are the type, by original designation: Clielifer can- ranges secured by measuring four males. croides var. nigripalptis Ewing.

Body length 2.55-3.2 mm.; palpal femur Idioc/ielifer Chamberlin. Hotf (1946 J, p. 486).

1.16^1.29 mm. long, 0.21-0.25 ' wide, mm. Diagnosis.—Cephalothorax a little longer ength 5.2 to 5.55 times the width; tibia 0.95 than wide, with a few large, seta-bearing -1.15 mm. long, 0.24—0.275 mm. wide, length tubercles scattered among the investing i.85 to 4.1 times the width; chela exclusive granules; cephalothorax with two cross fur- )f 1.6-1.85 pedicle mm. long, 0.4—0.475 mm. rows; eyes present. Tergites divided, those .vide, length 3.9 to 4.1 times the depth: of the male with crests or keels. Each coxa rhelal hand exclusive of pedicle 0.75-0.9 of the fourth leg of the male with a coxal Tim. long, 0.36-0.45 mm. deep; movable sac and lateral spur; subterminal setae of rhelal finger 0.85-1.05 mm. long. the tarsus of the fourth leg toothed, not Pe.male. ratios —Measurements and are simple; tarsus of the first leg of the male jiven as the of range four females. Body \\ithout a terminal spine; claws of pedal length 3.3-3.7 1.15-1.2 mm.; palpal femur tarsi simple except one claw of first leg 0.21-0.25 nm. long, mm. wide; length of of male with a well-developed accessory femur 4.75-5.45 times the width tibia ; palpal tooth: tarsus of the fourth leg with a tactile 3.95-1.05 mm. long, 0.24-0.28 mm. wide, seta distad from the mid-point. Cribriform length 3.75 to 4.1 times the width; chela plates of female genitalia moderately small. exclusive of pedicle 1.55-1.8 0.37- mm. long, Among several females observed as be- D.46 mm. wide, length 3.95 to 4.25 times longing to the species nigripalpus, there was ihe width ; hand exclusive of pedicle 0.75-0.85 found one in which many of the tarsal claws [Jim. long, 0.35-0.45 deep; movable mm. of the legs have an accessory tooth. This is 0.85-1.0 finger mm. long. clearly an anomaly and does not necessitate Distribution.—This cosmopolitan species a modification of the generic diagnosis. is invariably associated with man and may The only species known in the genus be found in dwellings, barns, granaries, bee- occurs in Illinois. llives, and the nests of such birds as sparrows and starlings (Hof^ 1944«). One col- Idiocht'Ufer nigripalpu.i (Ewing) lection in the present lot was taken from

:attle. Although the species is thought to Clielifer muricatus Say, in part? (1821, p. 63). — ;

488 Illinois Natural History Survey Bulletin Fol. 24, An. 4

Chelifer cancroides var. niiiripaipus Ewing here. Diagnostic parts are illustrated in figs. (1911, p. 73). 49.^-496'. 1931a, Chelifer tili/ripul/'iis Ewing. Chamberlin ( Male.—Important measurements are 52). p. given as the range of three males from Illi- Idiochelifer nigripalpus (Ewing). Chamberlin nois. Body length 2.1-2.35 mm.; carapace (1932, p. 19), Hoff (1946<-, p. 26). 0.8 mm. long, ocular width 0.39-0.4 mm. Hysleroc/ielifn lonijidnclytus Ho(f (1945/', p. Palpal femur 0.78-0.84 mm. long, 0.18-0.185 511). mm. wide, length 4.35 to 4.55 times the It is probable that Say (1821) included width; tibia 0.64-0.71 mm. long, 0.21 mm. specimens of Idiochclijer nigripiilpiis in his wide; chela without pedicle 1.36-1.41 mm. collection of Chelifer niuricatus. Since types long, 0.31-0.32 mm. wide, length 4.3 to 4.4 are not intact and since Say apparently based times the width ; chelal hand e,xclusive of his description on several species, including pedicle 0.63-0.65 mm. long, movable chelal Chelifer eancroides as indicated by the finger 0.76-0.80 mm. long. Female.—Measurements of the palpal segments and body length are the ranges of four mounted females; other measurements are given as the ranges of three mounted individuals. Body length (abdomen somewhat contracted in some specimens) 2.1-2.55 mm.; carapace 0.82-0.86 mm. long, 0.8-0.86 mm. wide across the posterior margin; ocular width 0.4—0.44 mm. Chelicera about 0.24 mm. long, base 0.14—0.15 mm. wide; movable finger, fig. 495, 0.18-0.195 mm. long. Palp, fig. 49^^, with maxilla 0.4-0.45 mm. long, 0.26-0.29 mm. wide; trochanter about 0.43 mm. long, 0.24—0.25 mm. wide; femur 0.82-0.87 mm. long, 0.19-0.195 mm. wide, length 4.3 to 4.6 times the width; tibia 0.65-0.71 mm. long, 0.22-0.23 mm. wide, length 2.95 to 3.2 times the width chela exclusive of pedicle 1.37-1.43 mm. long, 0.34—0.35 mm. wide, length 3.95 to 4.1 times the width; chelal hand exclusive of pedicle 0.65-0.68 mm. long, about 0.31 mm. deep; movable finger 0.75-0.79 mm.

Fig. 49. Idiochelifer niijripalpus 5 . J, long. First leg with pars basalis 0.148-0.163 dorsal view of palp; B, end of movable cheli- mm. deep, pars tibialis 0.137-0.14 mm. deep; ceral finger; C, lateral view of chela. entire femur about 0.5 mm. long; tibia 0.33-0.35 mm. long, 0.095-0.1 mm. deep; record from a house, Chelifer niuricatus tarsus 0.35-0.37 mm. long, 0.072-0.076 mm. must for all practical purposes be considered deep. Fourth leg with pars basalis 0.167- a no men nudum. 0.18 mm. deep, pars tibialis 0.243-0.265 mm. In the original description of this species, deep; entire femur about 0.7 mm. long; tibia no type specimens were indicated. Several 0.51-0.53 mm. long, 0.132-0.145 mm. deep; specimens in the Cornell University collec- tarsus 0.4—0.415 mm. long, about 0.095 mm.

tion are undoubtedly the types of the species, deep ; tactile seta located 0.28-0.30 mm. from and one of these, from Ames, Iowa, was the proximal margin of the tarsus. designated recently as the lectotype (Hoff Distribution.—This species is known 1946f). from several north-central states, including Since the type specimens of this species Illinois, Iowa, and Wisconsin. Undoubtedly have been described in some detail (Hoff several of Ewing's (1911) records of can- 1946f) and the females have been described croides apply to this species. In the Museum (Hoff 1945A) under the name Hystero- of Comparative Zoology is a mounted chelifer lougidactylus Hoff, only selected female from Areola (Douglas County), Illi-

measurements of Illinois specimens are given nois, that is labeled Chelifer cancroides and —

PsiiLIDIISCORI'HINS I)]' ll.l.lNdlS Juiu . I'UO HoFF: 489

that apparently was reported under tliis margin as from the median furrow; one pair designation by Ewing. A mounted male of of eyes. Icrgites, including the eleventh, this species from Clark County, Illinois, in divided; lateral keels of the male wanting the Ewing collection at Cornell is labeled or very weakly developed. Flagellar setae Chelijcr caiuroidis and apparently was not of chelicera entire. Movable chelal finger included among the records given by E\\ ing with si nearer sb than to / and fixed finger for Illinois. These and other records indi- with est and ;.s7 on nearly the same level cate a scattered distribution for the species and considerably proximad from the mid- over the central and northern parts of Illi- point of the finger. Coxa of the fourth leg nois. of the male with coxal sac; spurs of coxa Seven of the Illinois collections of this IV" lacking. Subterminal setae of the fourth species were made from the bark of living tarsus weakly toothed. Tarsus of the first trees, chiefly oaks an

1909, H. E. Ewing, 12 (mcz). Fox The genotype, the only species known i[i Lake: June 11, 1947, Burks & Stannard, 2 the genus, occurs in Illinois. specimens. Ho.mer: July 3, 1944, H. H.

Ross. 1 9. Mahomet: July 10, 1943, Ross Paisochelifer callus (Hoff) & Beaver, 19,1 tritonvmph. Marshall: llysteroihrlifer callus Hoflf (1945/^ p. 515 1. Oct. 31, 1908, J. L. Pricer, M (cu). Paisoclietifrr callus (Hoff). Hoff ( 1946(/, p. Rockford: Nov. 29, 1944, C. L. Remington, 487). 19 (cr). Starved Rock State Park: The adults of this species have been de- July 12. 1944. Prison & Sanderson, 1 9. scribed in detail in the original description (Hoff 1945/)). Included here are additional 26. PAISOCHELIFER Hoff data relative to the measurements of the

Paisoc/ielifer Hotf (1946./, p. 487). Genotype body and palp, and illustrations of important

by original designation : Hysierocheliler structures, figs. 50A-50E. The deutonymph, callus Hoff. previously unknown, is described in more Dlagnosis. —Carapace wider than long, detail. uniformly granular; transverse furrows Male.—Measurements given as the range deeply impressed, the posterior furrow about of three individuals, including the holotype. one-half as far from the posterior carapacic Body length 1.68-1.95 mm.; carapace 0.58-

w, i7~ nr

Fig. 50. Paisot hflifcr callus. A, end of m(j\'able cheliceral Hnger, ^ (many individuals, including the holotype, have two or three terminal and subterminal denticles on the apical tooth) ;

B, setal map of left half of eighth abdominal tergite, holotype i ; C, lateral view of chela, holotype o ; D, lateral view of terminal claw of first leg, holotype i ; £, dorsal view of palp, allotype 9 . ; ;;

490 Illinois Natural History Survey Bulletin Fo!. 24, Art. 4

0.61 mm. long, greatest width 0.61-0.75 Palp.—Moderately granular except the mm., ocular breadth 0..^2-0..36 mm. Palp chelal fingers, investing setae much as in the with trochanter 0.27-0.28 mm. long, 0.165- adult; segments, with the possible exception 0.175 mm. wide, length 1.57 to 1.7 times of the chela, conspicuously stouter than in the width; femur 0.52-0.56 mm. long, 0.155- the adult. Trochanter about 0.18 mm. long, 0.165 mm. wide, length .S.35 to 3.5 times the 0.12 mm. wide. Femur subcylindrical, wid- width; tibia 0.47-0.5 mm. long, 0.18-0.197 ened gradually toward the distal end, pedicle mm. wide, length 2.5 to 2.65 times the width almost wanting; both flexor and extensor chela exclusive of pedicle 0.89-0.945 mm. margins nearly straight; 0.312 mm. long,

long, 0.27-0.295 mm. wide, length 3.2 to O.I 1 mm. wide. Tibia with weakly developed 3.45 times the width; chelal hand 0.41-0.46 pedicle much wider than long; flexor margin

mm. long exclusive of pedicle, 0.23-0.28 mm. very weakly convex ; extensor margin flatly deep; movable chelal finger 0.5-0.53 mm. convex; 0.285 ram. long, 0.133 mm. wide. long. Serrula exterior of the movable cheli- Chela as viewed from the dorsum with both ceral finger with 17 or 18 plates. margins of hand moderately convex, the Female.—Measurements given as the flexor more so than the extensor; hand range of five females, including the allotype gradually narrowed toward the finger base and two paratypes. Body length 1.55-2.15 fingers evenly and gently curved; chela ex- mm.; carapace 0.63-0.69 mm. long, width clusive of pedicle 0.61 mm. long, 0.185 mm.

usually a little greater than the length but wide ; chelal hand exclusive of pedicle 0.29 less than the length in one individual; ocular mm. long, 0.167 mm. deep; movable finger width 0.35-0.38 mm. Palp including tro- 0.33 mm. long. Viewed from the side, chelal chanter 0.26-0.3 mm. long, 0.16-0.18 mm. hand appears subcylindrical, ventral margin wide, length 1.55 to 1.66 times the width; nearly straight, dorsal margin a little con- femur 0.59-0.61 mm. long, 0.165-0.175 mm. vex; fixed finger nearly straight, movable wide, length 3.45 to 3.65 times the width; finger slightly curved. Marginal teeth of tibia 0.48-0.54 mm. long, 0.19-0.205 mm. the chelal fingers much like those of the wide, length 2.4 to 2.7 times the width; adult except the teeth of the basal one-half chela of palp exclusive of pedicle 1.0-1.07 of the row of the movable finger are acuspid mm. long, 0.285-0.315 mm. wide, length 3.2 about 25 teeth on each finger. Movable

to 3.5 times width ; chelal hand exclusive of finger with two tactile setae: one (prob- pedicle 0.48-0.51 mm. long, 0.26-0.295 mm. ably t) located a little proximad from the deep; movable finger 0.53-0.59 mm. long. mid-point of the finger; the second (probably Deutonymph.—Body and legs light yel- sh) located twice as far from the first as lowish-brown, palps a little darker; body from the proximal margin of the finger; fairly stout, appendages usually stouter than nodus ramosus located a little distad from in the adult. Body length 1.3 mm. Cara- the mid-point of the finger. Fixed finger pace shaped much as in the adult; furrows with six setae: et a little less than one-third

less well impressed than in the adult; six of the finger length from the tip; it a little

setae along the posterior carapacic margin; closer to et than the latter is to the finger length of carapace 0.44 mm., posterior and tip; est removed from et by about the dis-

greatest width 0.43 mm.; ocular width 0.25 tance of et from the finger tip; both it and mm. Tergites divided, marked by netlike est proximad from the mid-point of the sculpturing; nearly all tergal halves with finger; one exterior and two interior basal three setae similar in nature to those of the and subbasal setae placed much as in the adult. Most sternites weakly divided, with adult probably missing setae are ist and ;

very weak, scalelike markings; usually three esb ; nodus ramosus located less than two setae on each half-sternite. Stigmatic plates areolar diameters basad from tactile seta et. and pleural membranes as in adult; abdomen Legs.—General characteristics as in the 0.85 mm. long, about 0.52 mm. wide. adult but much lighter in color, less sclerotic, Chelicera.— In general, similar to the and segments smaller and stouter. All tarsal chelicera of the adult except lighter in color claws simple. First leg with pars basalis and smaller; subbasal seta of palm of hand 0.08 mm. deep; entire femur 0.209 mm. long; wanting; galea with four simple rami; ser- tibia very stout throughout, 0.133 mm. long, rula exterior with 14 plates; chelicera 0.155 0.06 mm. deep; tarsus subfusiform, narrow- mm. long; base 0.085 mm. wide; movable ing in the distal half, 0.173 mm. long, 0.05 finger about 0.1 mm. long. mm. deep. Fourth leg with the pars tibialis —

June. 1949 Hoff: Pseudoscorpioxs of Illinois 491

0.103 mm. deep; entire femur 0.285 mm. Dl.AGNOSis.—Carapace longer than wide, long; tibia 0.194 mm. long, 0.071 mm. deep; moderately and regularly granular, with two tarsus 0.209 mm. long. 0.057 mm. deep; the cross furrows. Eyes present. Tergites di- tarsus subtusitorm, becoming much nar- vided, those of the male without lateral keels rowed in the distal one-hall and bearing a or with very weakly developed keels. Setae tactile seta that is located 0.145 mm. from of body and palp short, toothed, or weakly the proximal margin of the segment. clavate. Palps moderately slender, with uni-

DiSTRlBLTiox.—This species is known formly granular surface; tactile seta ;/ about only from Illinois. It was described originally in the middle between ct and ist or some- from Zion, and since then another collec- what nearer to ft, fig. 516'. Anterior tarsus tion has been taken in the same locality. of the male always strongly modified, the

Fi^. 51. Dactylin helijrr copinsus 9. A, dorsal view of palp; B, setal map of left half of eighth abdominal lergite; C, lateral view of chela.

The type series was collected on March 17. claws asymmetrical; tarsal claws of other 19.?.^, from sand and grass roots in dunes legs simple; subterminal setae of the tarsi area, Prison & Mohr, 1

2 ? , 1 deutonymph. the nearctic region, and this has been taken in Illinois. Other species of the genus occur Tribe D.^GTYLOCHELIFERINI throughout the palearctic region.

In this tribe, the males usually have a Dactylochelifer copiosus Hoff well-dififercntiated atrium in each coxal sac Ijuctylochelifcr lopiosus HofF (1945rt, p. 53; of leg I\' and the sclerotic rod and anterior 1945A, p. 521). invagination of the statumen convolutum Adults of this species have been described are always absent from the genital complex, in detail in the original description (Hoff fig. 10. The female has the medial pair of 1945fl). Additional data relative to the cribriform plates fused into one medial plate. limits of range in size of the palpal segments Only one certain genus and one species are and illustrations of important structures, found in North America. figs. 10, 47, 5 1,^-5 R-, are given here. In addition, brief descriptions are presented for 27. DACTYLOCHELIFER Heier the heretofore undescribed nymphal stages.

Utittylui/ielifir Beicr (l";32rt. p. 6+; 1932;, p. iM.ALE.—Measurements given as the limits 253). Genotype, by original designation: of range were secured by measuring 11 indi- Clielifer latreillei Leach. viduals from Illinois. Body length 2.3-2.6 ;

492 Illinois Natural History Survey Bulletin f'ol. 24, Art

mm. Palpal femur 0.8-0.91 mm. loiif;, 0.19.?- width; tibia 0.35-0.37 mm. long, 0.13-0.1 0.215 mm. wide, lenj;tli 3.9 to 4.25 times the mm. wide, length 2.55 to 2.7 times the wid width; tibia 0.72-0.82 mm. long, 0.225- chela 0.68-0.715 mm. long, 0.18-0.195 n^ 0.245 mm. wide, length 3.0 to 3.4 times the wide, length 3.6 to 3.85 times the wid width; chela 1.21-1.36 mm. long, 0.3-0.33 chelal hand 0.34-0.39 mm. long, 0.17-0.1 mm. wide, length 3.85 to 4.35 times the mm. deep ; movable finger 0.34—0.37 m width; movable chelal finger 0.66-0.72 mm. long. Movable chelal finger with two set long. one near the proximal margin, the otl Female.—Measurements given as the near the mid-point of the finger; homolog limits of range secured from seven individu- uncertain. Fixed finger with three exter als from Illinois. Bodv length 2.-1—3.15 mm. setae, either eb or esb wanting; three Palpal femur 0.82-0.91 mm. long, 0.19-0.22 terior setae as in the tritonymph except mm. wide, length 3.9 to 4.6 times the width relatively closer to the level of est. E; but usuallv 3.9 to 4.2 times the width; tibia chelal finger with about 35 marginal teet! 0.74-0.85 mm. long, 0.225-0.245 mm. wide, Proton YMPH.—Measurements based length 3.2 to 3.55 times the width ; chela five individuals. Appendages and be exclusive of pedicle 1.26-1.43 mm. long, smaller than in the deutonymph. Palpal Si

0.33-0.355 mm. wide, length 3.75 to 4.25 ments smaller and, with exception of ' times the width ; chelal hand exclusive of chela, appreciably stouter than in the deu pedicle 0.61-0.72 mm. long; movable finger nymph. Body 1.15-1.3 mm. long. Serri between 0.7 and 0.75 mm. in length. exterior of chelicera with 12 plates. P Tritonymph.—Measurements given as with trochanter 0.17-0.18 mm. long, the limits of range of four individuals. In 0.11 mm. wide, length 1.6 to 1.8 times i general, in appearance much like the adult width; femur 0.28-0.29 mm. long, O.Qt

except a little lighter in color and the seg- 0.1 mm. wide, length 2.85 to 3.05 times i ments of appendages much smaller and often width; tibia 0.25-0.26 mm. long, 0.105-0 a little stouter. Body 1.8-2.4 mm. long. mm. wide, length 2.15-2.4 times the wid

Chelicera 0.195-0.22 mm. long, movable chela 0.55-0.58 mm. long, 0.145-0.16 n- finger 0.14—0.15 mm. long; 16 or 17 plates wide, length 3.55 to 3.8 times the wid in the serrula exterior. Palp with trochan- chelal hand exclusive of pedicle 0.27-0.3 nn ter 0.32-0.35 mm. long, 0.185-0.19 mm. long, 0.135-0.155 mm. deep; movable finj wide, length 1.65 to 1.85 times the width; 0.29 mm. long. Movable chelal finger w femur 0.55-0.65 mm. long, 0.15-0.17 mm. one tactile seta located about one-third wide, length 3.65 to 3.95 times the ^vidth the finger length from the proximal niarj; tibia 0.53-0.6 mm. long, 0.17-0.19 mm. wide, Fixed chelal finger with two exterior set length 3.1 to 3.25 times the width; chela one located less than one-third of the fin) 0.9-1.1 mm. long, 0.23-0.26 mm. wide, length from the tip and the other plac length 3.9 to 4.3 times the width; chelal near the base of the finger; a single si hand 0.46-0.56 mm. long, 0.21-0.25 mm. of the interior series located near the finf deep ; movable finger 0.50-0.54 mm. long. base. About 30 teeth on each chelal finge Fixed chelal finger with seven tactile setae, Distribution.—This species is kno' arranged much as in the adult except ist from only two states, Arkansas, from wh wanting and it placed a little closer to the it was originally described, and Illin( level of est than to the level of et. Movable from which it was recorded later (H finger with three setae, either b or sb want- 1945i). Illinois collections are from sc ing. About 40 or 45 marginal teeth on each tered localities over the state, with coll chelal finger. tions more abundant in the southern half Deutonv.mph.—Measurements given as Almost every collection was taken fn the range of size of five individuals. Ap- ground cover and litter, although one v pendages and body much like those of the made while sweeping vegetation with a n tritonymph except stouter and much smaller. Illinois Records.—All stages have b( Body length 1.45-1.6 mm. Serrula exterior collected from Burksville, Edwardsvil of 13 or 14 ligulate plates. Palp with tro- Gefif, Giant City State Park, Gillesp chanter 0.23-0.24 mm. long, 0.125-0.135 Grand Detour (Castle Rock), Havai mm. wide, length 1.75 to 1.85 times the Herod, Logan, Makanda, Murphysbo width; femur 0.38-0.40 mm. long, 0.11-0.12 New Columbia, Pere Marquette State Pa mm. wide, length 3.25 to 3.45 times the Vienna. ne, 1949 Hoff: Pseldoscorpioxs of Illinois 493

UNIDENTIFIED NYMPHS species. These undetermined cheliferid nymphs are from the foUouing counties: Several collections contain nymphs of Adams, Carroll, Hardin, Jackson, Jersey, leliteridae that I have found impossihle La Salle, Macoupin, Madison, Masoii, inadvisable to determine as to genus or Schuvler, and Union. LITERATURE CITED

Balzan, Luigi 1891. Cheinetes (Pseudoscoipiones). Societe entoniologique de France annales 60:497-552. 4 pis. Paris. Banks, Nathan 1890. A new pseuHoscorpion, Can. Ent. 22:152. 1891. Notes on North American Chernetidae. Can. Ent. 23:161-6. 1893. New Chernetidae from the United States. Can. Ent. 25:64-7. 1895. Notes on the Pseudoscorpionida. N. Y. Ent. Soc. Jour. 3:1-13. Beier, Max

1930fl. Neue Hohlen Pseudoscorpione der Gattung Cliihonius. Eos 6:232-7. 5 figs. Madrid. 1930i. Die Pseudoskorpione des Wiener Naturhistorischen Museums. Wiener Naturhistorisches Museum Annalen 44:199-222. 17 figs. Wien. 1932«. Zur Kenntnis der Cheliferidae (Pseudoscorpionidea). Zoologischer Anzeiger 100:53-67. Leipzig.

1932i. Pseudoscorpionidea. I. Subord. Chthoniinea et Neobisiinea. Tierreich 57:1-258. 271 figs. 1932f. Pseudoscorpionidea. II. Subord. Cheliferinea. Tierreich 58:1—294. 300 figs. 1932^^. Pseudoscorpionidea— Afterscorpione. In Kiikenthal Krumbach, Handbuch der Zoologie 3:117-92. 110 figs.

1933. Revision der Chernetidae (Pseudoscorp.) Zoologische Jahrbiicher, Abteilung fiir Systematik, Okologie und Geographic der Tiere 64:509—48. 15 figs. Jena. 1941. Pseudoscorpionidea—Afterscorpione. In Kiikenthal Krumbach, Handbuch der Zoologie 3:169-85. 19 figs.

Chamberlin, J. C. 1924. Hesperochernes laurae, a new species of false scorpion from California inhabiting the

nest of /V.(/i«. Pan-Pacific Ent. 1:39-90. 1 pi. 1925. On a collection of pseudoscorpions from the stomach contents of toads. Cal. Univ. Pubs.

Ent. 3:327-32. 16 fig.s. 1926. Notes on the status of genera in the chelonethid family Chthoniidae together with a description of a new genus and species from New Zealand. Dansk Naturhistorisk

forening i Kj0benhavn, Viedenskabelige Meddelelser 81:333—8. 1 fig. 1929a. D'lnocheirxis tcnoch, an hitherto undescnbed genus and species of false scorpion from Mexico. Pan-Pacific Ent. 5:171-3. 1929i. A synoptic classification of the false scorpions or chela-spinners, with a report on a cosmopolitan collection of the same.—Part I. The Heterosphyronida. Ann. Mag. Nat. Hist., Ser. 10, 4:50-80. 3 figs. 1929f. On some false scorpions of the suborder Heterosphyronida. Can. Ent. 61:152-5. 1930. A synoptic classification of the false scorpions or chela-spinners, with a report on a cosmopolitan collection of the same.—Part II. The Diplosphyronida. Ann. Mag. Nat.

Hist., Ser. 10, 5:1-48; 585-620. 3 figs. 1931fl. The arachnid order Chelonethida. Stanford Univ. Pubs., Univ. Ser., Biol. Sci. 7:1-284. 71 figs. 1931i. Parachernes ronnaii, a new genus and species of false scorpion from Brazil (Arach- nida-Chelonethida) Ent. News 42:192-5. 1 pi. 1932. A synoptic revision of the generic classification of the chelonethid family Cheliferidae Simon (Arachnida). Can. Ent. 63:289-94; 64:17-21, 35-9. (Volume 63 dated 1931.) 1934. On two species of false scorpions collected by birds in Montana, with notes on the genus Dinocheirus. Pan-Pacific Ent. 10:125—32. 1 pi. 1938. New and little-known false-scorpions from the Pacific and elsewhere. Ann. Mag. Hist., Ser. 11, 2:259-85. 6 figs.

Chamberlin, J. C, and R. V. Chamberlin 1945. The genera and species of the Tridenchthoniidae (Dithidae). Utah Univ. Buljj 35(23) :l-67. 17 figs. Ellingsen, Edv. 1909. Die Pseudoskorpione des Berliner Museums. Zoologisches Museum in Berlin MitteilJ ungen 4:357-423.

[494] \Jiiiic. 1949 Hoff: PsEi-noscoRpioxs of Illinois 495

Essig, E. O. 1929. Insects of we>tcrii North America. Macmillaii Company, N. V. 1035 pp. 766 tigs. Ewing. H. E. 1911. Notes on pseudoscorpions; a study on the variations of our common species, CItelijcr cancroides. Linn., with systematic notes on other species. N. Y. Em. Soc. Jour. 19:65-81. 15 figs. Feio, Jose Lacerda de Araujo 1941. Sobre um curioso pseudoscopiao. Papeis avulsos do Departmento de Zoologia

l:241-f. 1 fig. San Paulo. Fourcroy, Antoine Francois 1785. Emomologia parisiensis. 2 vols., 554 pp. Paris. Geoffroy, E. L. 1762. Histoire abregee des insectes (jui se trouveiit aux environs ile Paris. 2 vols.: 28 +

523 pp., 10 pis. ; 690 pp., 12 pis. Paris. Gervais, Francois Louis Paul 1849. In Gay Historia fisica y politica de Chile (Zoologica) 4:13. Paris. Hadzi, Jovan 1933a. Primos poznavanju pseudoskorpijske fauiie Primorja. Prirodoslovna istrazivanja Kraljevine Jugoslavije 18:125—92. Zagreb. 1933/'. Beitrag zur Kenntnis der Pseudoskorpioneii — Fauna des Kiistenlandes. Academic Vougoslave, Classe des sciences mathematii)ue> et iiaturelles Bulletin International 27:173-99. Zagreb. Hansen. Hermann 1869. The -American Pseudo-scorpions. Record of .'\merican Entomology for the Year 1868: 48-52. Salem. 1879. Hohlen-Chelifer in Nord-.\merica. Zoologischer .\nzeiger 2:399-4(10. Leipzig. Hermann, J. F. 1804. Mcmoire apterologique. 144 pp., 9 col. pis. Strasbourg. Hoff. C. Clayton 1944((. Notes on three pseudoscorpions from Illinois. Hi. State -Acad. Sci. Trans. 37:123-8. 2 figs. 1944A. New pseudoscorpions of the subfamily Lamprochernetinae. Am. Mus. Nat. Hist. Novitates 1271:1-12. 15 figs. 1945rt. New species and records of pseudoscorpions from Arkansas. Am. Micros. Soc. Trans. 64:34-57. 2 pis. 21 figs. 1945/'. New species and records of cheliferid pseudoscorpions. Am. Midland Nat. 34:511—22. 12 figs.

1945(". Pseudoscorpions from North Carolina. Am. Micros. Soc. Trans. 64:311—27. 12 figs. 1945J. Hesperocherncs canadensis, a new chernetid pseudoscorpion from Canada. .•\m. Mus. Nat. Hist. Novitates 1273:1-4. 7 figs. 1945c. The pseudoscorpion genus Alhinrix Chamberlin. Am. Mus. Nat. Hist. Novitates 1277:1-12. 20 figs. 1946rt. A redescription of two of Hagen's pseudoscorpion species. New Eng. Zool. Club.

Proc. 23:99-107. 6 text figs. PI. I with 10 figs. 1946i. Additional notes on pseudoscorpions from Illinois. III. State Acad. Sci. Trans. 38: 103-10. 1946<'. New pseudoscorpions, chiefly neotropical, of the suborder Monosphyronida. Am. Mus. Nat. Hist. Novitates 1318:1-32. 32 figs. 1946t/. The pseudoscorpion tribe Cheliferini. Chicago Acad. Sci. Bui. 7:485—90. 1946<'. American species of the pseudoscorpion genus Microhisnim Chamberlin, 1930. Chicago .Acad. Sci. Bui. 7:493-97.

1946/. A study of the type collections of some pseudoscorpions originallv tlescrlbed by- Nathan Banks. Wash. .Acad. Sci. Jour. 36(6) :195-205. 8 figs. 1947. The species of the pseudoscorpion genus i'.lwlanops described by Banks. Har\'ard Univ. Mus. Compar. Zool. Hul. 98:473-550. 37 figs. iew, H. W. 1912. On the pairing of pseudoscorpiones. Zool. Soc. London Proc. 376—90. ioch, C. L. 1843. Die Arachniden 10:37-80. Pis. 337-347. Niirnberg. Linnaeus, Carolus 1758. Systema naturae, tenth edition 1. 2 + 824 pp. Helmiae. 496 Illinois Natural History Survity Hulletin I'lil. 24. An. 4

Preyssler, J. D. E. 1790. V'erzeichniss bohmischer Insecten. 108 pp., 2 col. pis. Prague. Roewer, C. Fr. 1936- Cheloncthi otier Pseudoskoipione. /« Broiin, H. G., Die Klassen und Ordnungen

1937. des Tierreichs 5:div. 4, book 6, no. 2, 1-320. Leipzig. Ross, Herbert H. 19+4. How to collect and preserve insects. 111. Nat. Hist. Surv. Circ. 39:1-55. 63 figs. Say, Thomas 1821. An account of the Arachnides of the United States. Acad. Nat. Sci. Phila. Jour. 2:59-82. Simon, Eugene 1879. Chernetes. Les Arachnides de France 7:1-78. Paris. Stecker, Anton 1875. Ueber zweifelhafte Chernetiden-Arten, welche von A. Menge beschrieben wurdcn. Deutsche (Berliner) Entomologische Zeitschrift 19:305-14. Tomosvary, O. 1882. Pseudoscorpiones Faunae Hungariae. Matematikai es termeszettudomanyi Kozle- menyek 18:135-256. Budapest. Vachon, Max 1940. Remarques sur la phoresie des pseudoscorpiones. Societe entomologique de France Annales 109:1-18. Paris. 1941rt. Chthonius tetrachetaius P. et ses formes immatures (1" note). Museum national d'histoire naturelle Bui. 13:442-9. 23 figs. Paris. 1941//. Chlhniiius tetraihelatus P. et ses formes immatures (2" note). Museum national d'histoire naturelle Bui. 13:540-7. 6 figs. Paris. 1947. Nouvelles remarques a propos de la phoresie des pseudoscorpiones. Museum national d'histoire naturelle Bui. 19:84-7. Paris. INDEX

The page entries in boldface type refer to the principal treatment of various categories from suborders to subspecies and varieties. Names that are synonyms, or of changed generic assignment, are indicateit by itaiu type.

A D

Acuminochernes, 455, 476 Oaclylochelifer, 486, 491 aflinis, Chelanops, 461 Dactylocheliferini, 428, 491 Albiorix, 444 l^endrochernes, 455, 464 Allochernes, 465 lienltilus, Chelanops, 478 Alura, 429 dt-titatus, Chelijer cancroides, 486, 487 Apocheiridium, 449 Ji-nlatus, Chnncs, 448, 478 .\pochthonius, 432, 434 dentatus, Mirochernes, 415, 418, 428, 478 .^temnidae, 417, 449, 485 Dinocheirus, 456, 471, 474 Diplosphyronida, 413, 426, 428, 443 B distinctus, lllinichernes, 418, 428, 481 dorsalis, Dinocheirus, 474 brunneum, Microbisium, 416, 418, 428, 445. 446 hrunneum, Ubisium, 444, 445 E

Q, ellipticus, Lamprocherncs, 450 clongatus, Paratemnus, 485 nillus. Hysleroc/ielifir, 489 Ephippiochthonius, 433 callus, Paisochelifer, 416, 418, 428, 489 crosidens, Miimlochthoiiius, 436 lancroides, Ararus. 486 evvingi, Reginachernes, 418, 428, 465, 466, 467 cancroides, Chelifer, 414, 416, 418, 428, 486, 487, 488, 489 F carolinensis, Neobisium, 444 Cheiridiidae, -^9 Feaelloidea, 449 Cheiridioidea, 449 Chelanops, 455, 460, 461, 466 G Chelifer, 486 Chcliferidae, 426, 428, 449, 485, 493 Garypiiiae, 477 Cheliferinae, 426, 428, 485 CJarypoidea, 446 Cheliferini, 428, 486 Garypus, 415, 447, 449 Cheliferoidea, 449 gigas, Microcreagris, 444 Chernetidae, 426, 428, 449, 485 tiraminella, 188, 263 Chernetinae, 428, 450, 455, 485 granulata, Larca, 416, 418, 428, 447 Chitra, 444 t/ranulatus, Garypus, 447 Chthoniidae, 428, 429, 431 grossus, Lamprocherncs, 450 Chthoniinae, 428, 431 Chthoniini, 428, 431, 443 H Chthonius, 432. 433 chyzeri, Lamprocherncs, 453 Hesperochernes, 455, 465, 476, 481 coecus, Chelifer, 460 Helerochthonius, 432, 434 communis, Pseudozaona, 471 lletcrosphyronida, 413, 426, 428, 429 confusum, Microbisium, 415, 418, 428, 445, 446 Ilyarinus, 444 copiosus, Dactylochelifer, 415, 418, 428, 491 fortuis, Chelanops, 468, 494, 485 1 corticis, Chelanops (?), 418, 428 corticis, Cjcnus ?, 455, 484 Ideoroncidae, 443, 444 crassopalpus, Acuminochernes, 415, 418, 428, Ideohisiinae, 444 477, 478 Idiochelifer, 486, 487 crassopalpus, Hesperochernes, 476, 477 llliruchernes, 455, 481 crosbyi, A pochthonius, 434, 436 intermedins. Apochthonius, 434 crosbyi, Heterochthonius, 434, 436 ischnocheles. Chelifer, 433 cyrneus, Chernes, 464 ischnocheles, Chthonius, 418, 428, 432, 433

[497] History Survey Bulletin Vol. 24, Art. 4 498 Illinois Natural

pallidus, Chelanops, 456, 472 pallidus. Chernes, 456, 472 Lamprochernes, 450 pallidus, Dinocheirus, 415, 418, 428, 472 Lamprochernetinae, 428, 450 pallidus, Hesperochernes, 472 Larca, 447 Parachernes, 455, 456 latreillei, Chelljer, 491 parvulum, Microbisium, 445 latus, Garypus, 447 parvus, Pselaphochernes, 415, 418, 428, 461 laurae, Hesperochernes, 476 pennsyh'anicus, Clithonius, 433 Inngidactylus, Hysterochelifer. 488 Pensylt'anicus, Chthonius, 433 longipalpus, Clithonius, 433 Pselaphochernes, 455, 461 Lustrochernes, 450 Pseudogarypidae, 449 lymphatus, Reginachernes, 418, 428, 465, 467, Pseudogarypus, 449 468 Pseudozaona, 455, 471 pulchellus, Parachernes, 456 M R maculaUis. Clilliomus tetraclielalus var., 433 Menthidae, 447 Reginachernes, 456, 465 Menthus, 447 ronnaii, Parachernes, 456 Microbisium, 415, 444 rossi, Mundochthonius, 416, 418, 428, 436, 437 Microcreagris, 444 minor, Lamprochernes, 418, 428, 450, 453 mirabilis, Pseudozaona, 471 Mirochernes, 455, 456, 478 sanborni, Chelanops, 456, 466 moestus, Apochthonius, 415, 418, 428, 434 sanborni, Hesperochernes, 466 moesttis, Clithonius, 434 sandersoni, Mundochthonius, 415, 418, 428 449 Monosphyronida, 413, 415, 426, 428, 429, 437, 440 morosus, Chelanops, 466 scorpioides, Chelifer, 461 morosus, Dendrochernes, 464, 466 scorpioides, Pselaphochernes, 461 multispinosns, Heterochthonius, 415, 418, 428, solus, Dinocheirus, 418, 428, 474 I 434, 436 spinosa, Verrucaditha, 415, 418, 428, 429, 430 Mundochthonius, 432, 436 spinosus, Clithonius, 429 muricatus, C/ielifer, 486, 487, 488 squarrosus, Parachernes, 415, 418, 428, 456, muscorum, Obisium, 444 472 Sternophoridae, 449 N Sternophorus, 449 Syarinidae, 443, 444 Neobisiidae, 428, 443, 444 Syarinus, 444 Neobisiidea, 417 Neobisiinae, 428, 444 Neobisium, 444 nigripalpus, Chelifer, 488 tenoch, Dinocheirus, 471 444 nigripalpus, Chelifer caneroides var., 487, 488 tenuis, Neobisium carolinensis var., 418, 428, nigripalpus, Idiochelifer, 415, 418, 428, 487, 488 tetrachelatus, Chthonius, 415, 416, nodosus, Chelifer, 450 433 nodosus, Lamprochernes, 453 tetrachelatus, Scorpio, 433 Tridenchthoniidae, 417, 428, 429 o Tridenchthoniinae, 428, 429

ohlnngus, Chelanops, 450 u ohlongus, Chelifer, 450 oblongus, Lamprochernes, 415, 418, 428, 450, unicolor, Hesperochernes, 476 453 uniformis, Pseudozaona, 471 occidentalis, Apochthonius, 434 Olpiidae, 447 orlhodactylum, Obisium, 432 ozarkensis, Microcreagris, 444 Verrucaditha, 429 Verrucadithini, 428, 429 virginica, Chelanops, 456 virginicus, Parachernes, 456 packardi, Blothrus, 443 packardi, Chthonius, 443 w packardi. Genus ?, 432, 443 Paisochelifer, 486, 489 Withiinae, 485 INDEX

The following index covers Article 3 of V'oliime 24 of the Illinois Natural History Survey

Bulletin. An index of Article 1, T/ie Mosquitoes of Illinois (Diptera, Culicidae) , by Herbert

H. Ross, begins on page 95 of this volume. An index of Article 2, The Leafhoppers, or Ciia- dellidae, of Illinois (Eurymelinac—Balcliithinae), by D. M. DeLong, begins on page 367 of this volume. An index of .Article 4, Tlie Pseudoscorpions of Illinois, by C. Clayton Hotf, begins on page 497 of this volume.

Algae, 386, 391, 410, 411 Caddis worms Anacharis canadensis, 407 Molannu, 407 Annuli (annual rings), 388, 390, 393-5, 411 Oecetis inconspicua, 407 close spacing of, 395, 411 Ortholrichia, 407 false, 393-5, 411 Oxyethira, 407 overlapping, 395 Camharus skipped, 395, 411 propinquus, 387, 407; see also Crayfish Anodontia grandis, 384 virilis, 387, 407; see also Crayfish

Aphanizomenon flos-a(/nae, 386, 411 ; see also Carp, 377 Algae Chelydra serpentina, 387; see also Turtles Aquatic beetle larvae, 399, 407 Chrysemys picta marginata, 387; see als Dytiscidae, 407 Turtles Dytiscus, 407 Circuli, 393, 394 Haliplidae, 407 Cladocera, 399, 410 Haliplus, 407 Clams, 384 Pellodytes, 407 Crappies, 377

Hydrophilidae, 407 Crayfish ; see also Camharus Berosus, 407 in Fork Lake, 387 Enochrus, 407 in stomachs of bass, 399, 403

Aquatic insects ; see references to aquatic insect groups D

Aquatic vegetation ; sec references to plant species Damselflies, 399, 403, 407 Enallagma, 407 B Die-off of plants, 386, 390, 391, 411 Diptera larvae, 399, 403, 411 Back swimmers, 399 Ceratopogonidae (biting midges) Bass; see Largemouth bass Bezzia, 403 Black bullheads, 377 Palpomyia, 403 "Bloom" of algae, 386, 391, 392 Prohezzia, 403 Bluegills, 377-412 Chaoboridae condition and growth, 391-3, 411, 412 Chaoborus, 403 food analysis, 398-407, 411 Chironomidae (midges) growth rates, 387-91, 411, 412 Cliironomos, 403 histological study, 397, 398, 411 Tanypus, 403 Index of Condition, 391-3 Culicidae (mosquitoes) scale analysis, 393-5, 411 Culex, 403

sexual cycle, 397, 398, 411 Simuliidae (black flies) spawning and young fish, 395-7 Simulium, 403

Buffalo, redmouth, 377 Stratiomyidae (soldier flies) Bullfrogs, 387; see Iso Rana catesbeiana Odontomyia, 403 Bullheads, 377 Stratiomys, 403

[499] 500 Illinois Natural History Survey Bulletin Volume 24

Dragonflies, 399, 403, 407 Leopard frogs, 403, 407 Epicordulia, 407 Lepomis macrochirus, 377; see also Bluegills M

Entomostraca, 386, 399, 403, 407, 410, 411 Mayfly nymphs, 403 Cerwdaphnia, 407 Micropterus salmoldes, 377; see also Large- Cyclops, 407 mouth bass Cypris, 407 Midges, 399; see also Diptera larvae Daphnia, 399, 403, 407 MoUusks; see also Snails Diaptomus, 407 Musculium, 407 planorbis type snails, 407 Physa, 407 Mount Zion, Illinois, 377, 38 411 Fork Lake, 377-412 condition and growth of fish, 391-3, 411 cropping procedure, 378—81, 411 N 380, 381, by use of hook and line, 377, 378, Naiad, 387 411 Najas guadalupensls, 387 by use of seines, 377, 380, 381 by use of wing nets, 377, 378-81, 387, 407, o 411 dam failure, 382-5, 411 Oxygen, 410 fish yield, 381, 382, 411 foods of bass and bluegills, 39C-407, 411, 412 growth rates, 387-91, 411, 412 open water areas, 386, 387 Pondweed, 386, 411; sec also Potamogeton and pond habitat, 385-7, 411 Polamogeton scale analysis of fish, 393-5, 411 Potamogeton, 386, 391, 396, 410, 411; see also sexual cycle of fish, 397, 398 Potamogeton, below spawning and young fish, 395—7, 411 Potamogeton; see also Potamogeton, above vegetation vs. fish yield, 387, 411 foliosus, 386, 387, 399, 407, 411 nodosus, 386 H Hairworms R Gordius, 407 Rana Hemiptera catesbelana, 384, 387, 407 Corixa, 407 pipiens, 407 ; see also Leopard frogs Notonecta, 407 Ridge Lake, 397, 398 Homewood Lake, 377, 388

411 Illinois River, 379 Snails, 399, 403, 407, Illinois State Department of Conservation, Spirogyra, 381, 396 378, 381

Tadpoles, 387, 403, 407 Lake Glendale, 397, 398 Terrestrial invertebrates, 407 Largemouth bass, 377-412 Turtles condition and growth, 391-3, 411 snapping, 387 food analysis, 398-407, 411 painted, 387 growth rates, 387-91, 411 histological study, 397, 398, 411 w Index of Condition, 391-3 scale analysis, 393-5, 411 Water boatmen, 399 sexual cycle, 397, 398, 411 Water strlders spawning and young fish, 395-7, 411 Gerris, 407

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