NovttatesAMERICAN MUSEUM PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET NEW YORK. N.Y. 10024 U.S.A. NUMBER 2707 FEBRUARY 26, 1981

ROBERT J. RAVEN AND NORMAN I. PLATNICK A Revision of the American of the Family (Araneae, ) i.. AMERICAN MUSEUM Norntates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 2707, pp. 1-20, figs. 1-54 February 26, 1981 A Revision of the American Spiders of the Family Microstigmatidae (Araneae, Mygalomorphae)

ROBERT J. RAVEN1 AND NORMAN I. PLATNICK2

ABSTRACT The tribal grouping Microstigmateae Roewer is Venezuelan species Pseudonemesia parva Ca- removed from the and elevated to fa- poriacco is described for the first time, and a new milial rank. The subfamily Pseudonemesiinae Ca- species, P. kochalkai, is described from Colom- poriacco is transferred from the to the bia. A genus (Ministigmata) described for a new Microstigmatidae. The family is suggested to be species (M. minuta) from Brazil is hypothesized the sister group of the Mecicobothriidae plus to be more closely related to the South African and Dipluridae. The male of the genus Microstigmata than to Pseudonemesia. INTRODUCTION The unusual mygalomorph spiders which (Dipluridae and Ctenizidae), neither of form the subject of this paper have been pre- whose defining features they share. viously studied by only three other arach- Hewitt (1916) had difficulty assigning the nologists: Hewitt (1916, 1925), Lawrence first known species, Microstigmata geophil- (1938), and Caporiacco (1955). The New um from Grahamstown, South Africa, to a World species, in particular, have long been family. He excluded the genus from the overlooked both because of their rarity in Ctenizidae because of the absence of a che- collections and their extremely small size liceral rastellum and placed it in the Dipluri- (adult males, reported here for the first time, dae, even though he was "unable to discover range from 1 to 3 mm. in total length and definite indication of close relationship to thus rival the mecicobothriid genus Hexu- any of the known genera" of that family. If rella and the diplurid genera Microhexura the species actually was a diplurid, the pres- and Masteria as the world's smallest myga- ence of two rows of teeth on the paired tarsal lomorphs). Moreover, these spiders illus- claws would associate it with the subfamily trate the difficulties currently plaguing the Diplurinae, and the short posterior lateral higher classification of mygalomorphs, hav- spinnerets would exclude it from diplurine ing been described in two different families subgroups other than the Brachytheleae and

I Assistant Arachnologist, Queensland Museum, Gregory Terrace, Fortitude Valley, Queensland 4006, Australia. 2 Associate Curator, Department of Entomology, American Museum of Natural History; Adjunct Professor, Department of Biology, City College, City University of New York.

Copyright ©) American Museum of Natural History 1981 ISSN 0003-0082 / Price $1.65 2 AMERICAN MUSEUM NOVITATES NO. 2707

FIGS. 1-4. Book-lung openings, ventral views. 1. Microstigmata sp., 560x. 2. Microstigmata sp., 2400x. 3. Sphodros sp. (Atypidae), 125 x . 4. Paratropis sp. (), 125 x. similar forms. However, Hewitt noted that of Microstigmata from Natal, gave no indi- Microstigmata lacks the tarsal scopulae typ- cation of his views on their affinities beyond ical of the Brachytheleae, and concluded labeling them as members of a "primitive only that the genus "can be considered as genus of four-lunged " (p. 460). one of the connecting links between the two Caporiacco (1955) had similar difficulties families Ctenizidae and Dipluridae" (1916, p. in placing his new Venezuelan spider, Pseu- 206). donemesia parva. He noted that it generally Discovery of the male of the species did resembled diplurids but (like Microstigmata) not lead Hewitt (1925) to change his assess- is excluded from that family by having short ment of the familial position of Microstig- posterior lateral spinnerets with short apical mata, but in addition to the Brachytheleae segments. He assigned the species to the he did indicate a possibly close relationship Ctenizidae and established for it the new to the family Paratropididae. Lawrence subfamily Pseudonemesiinae, differing from (1938), in describing two additional species most other ctenizids in having only two spin- 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 3

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FIGS. 5-10. Cuticle of tarsus I, dorsal views. 5. Pseudonemesia parva Caporiacco, 1150x. 6. P. kochalkai, new species, 1350x. 7, 8. Ministigmata minuta, new species; 7, 1300x, 8, 5250x. 9, 10. Microstigmata sp.; 9, 210x, 10, 2000x. 4 AMERICAN MUSEUM NOVITATES NO. 2707

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FIGS. 11-14. Claws of leg I, ventrolateral views. 11. Microstigmata sp., 240x. 12. Ministigmata minuta, new species, 1250x. 13. Pseudonemesia parva Caporiacco, 1050x. 14. P. kochalkai, new species, i1OOx. nerets and lacking a cheliceral rastellum. As ican species, has allowed us to present below the presence of a rastellum is virtually the a reassessment of these spiders and their re- only defining character of the Ctenizidae, lationships. We will first argue that Micro- Caporiacco's assessment is fully as proble- stigmata, Pseudonemesia, and the new matical as Hewitt's. Caporiacco did not as- species described below represent a distinct sociate Pseudonemesia with Microstigmata, and monophyletic group, and then inquire as probably because the small size of the former to what their sister group may be and how prevented him from observing some of the the various microstigmatid species may be characters they share. interrelated. Thus it is clear even from the literature that the present taxonomic positions of these MONOPHYLY two genera are untenable. The discovery of There are three characters that seem to be adult males that can be attributed to P. par- synapomorphies uniting the species treated va, as well as of two additional South Amer- below as microstigmatids: the tiny, oval 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 5

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FIGS. 15-20. Claws of leg I, lateral views (15-19), ventral view (20). 15. Ministigmata minuta, new species, 1160x. 16. Pseudonemesia kochalkai, new species, 750x. 17. Nemesia sp. (Ctenizidae), 240x. 18. Diplura sp. (Dipluridae), 240x. 19, 20. Diplothelopsis sp. (), 125x. 6 AMERICAN MUSEUM NOVITATES NO. 2707 I

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FIGS. 21-24. Cuticle and setae of leg I, dorsolateral views. 21. Paratropis sp. (Paratropididae), 240x. 22. Microstigmata sp., 240x. 23, 24. Ministigmata minuta, new species; 23, 1040x, 24, 2400x (whorled seta at base of claws). book-lung openings, the scaly cuticle of the begins to approach the microstigmatids in legs and palpi, and the tarsal claw dentition. this character is the Paratropididae. Some Hewitt (1916) first recognized the peculiari- paratropidids, particularly small ones, have ties of the book-lung apertures of Microstig- book-lung openings that are reduced in size mata. Whereas in other mygalomorphs the (perhaps an adaptation to living in, and hav- book-lungs open through long, transverse ing their bodies encrusted and camouflaged slits (figs. 3, 4), in Microstigmata the open- by, dirt), but they have a sclerotized rim only ings are unusually small oval pores com- along their anterior borders and generally re- pletely surrounded by a sclerotized rim, with tain the slit-like form found in other myg- the opening consisting "of a rather cribri- alomorphs (fig. 4). The peculiar book-lung form plate reminiscent of the stigmata of cer- openings of microstigmatids cannot be dis- tain insects, which is provided with a few missed as merely being adaptations to small minute black hairs on its surface" (Law- size and a resulting higher rate of water loss, rence, 1938, p. 460; figs. 1, 2). The only other for Microstigmata species are no smaller mygalomorph group known to us that even than many other mygalomorphs, and the 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 7

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FIGS. 25-28. Serrula, anterior views. 25. Microstigmata sp., 500x. 26. Ministigmata minuta, new species, 1250x. 27. Pseudonemesia parva Caporiacco, 725x. 28. P. kochalkai, new species, 600x. modifications do not occur in other tiny of atypid, antrodiaetid, hexathelid, and di- forms like Hexurella, Microhexura, and plurid legs can be found in Gertsch and Plat- Masteria. nick, 1979, figs. 5, 7, 9, 15, 17, 19, 21, 23, 25, Secondly, the microstigmatids are distinc- 27). Interestingly, spiders of the suborder tive in having the cuticle of the legs and ped- have similar (although less ele- ipalps covered with flattened scales, semi- vated) digitiform pustules (Gertsch and Plat- circular or triangular in shape and highest at nick, 1979, figs. 11, 13), as do a few species their distal ends. These are most easily seen of Dipluridae (Ixamatus and a related genus in Pseudonemesia (figs. 5, 6), but they also in the Diplurinae; Raven, 1980a, figs. 11-13), occur in Mfcrostigmata and the new genus but there are no scales underlying the pus- Ministigmata, where they bear numerous tules in those species. digitiform pustules (figs. 7, 9); the outlines of Finally, the form of the tarsal claws may the scales in these species are marked by also be synapomorphic for microstigmatids. longer pustules (figs. 8, 10). Such scales are The paired (superior) claws each bear two not known to occur in other mygalomorphs rows of teeth (figs. 11-14), a condition un- (comparable scanning electron micrographs usual among mygalomorphs but also found 8 AMERICAN MUSEUM NOVITATES NO. 2707

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FIGS. 29-32. Tarsal organ of leg I, lateral views. 29. Microstigmata sp., 50Ox. 30. Ministigmata minuta, new species, 5250x. 31. Pseudonemesia parva Caporiacco, 2800x. 32. P. kochalkai, new species, 1l,500x. in the Pycnothelidae, Dipluridae (Dipluri- claws of other diplurines (such as Teyl) re- nae), and some Ctenizidae (the Aporopty- semble this ctenizid condition more than the cheae and Nemesieae of Simon, 1892). How- pycnothelid one, a wider survey of claw den- ever, the teeth in microstigmatids may be tition is needed before much reliance can be distinctive in originating near the dorsal sur- placed on the character. face of the claws (figs. 15, 16) and resting alongside the claw itself. In the pycnothelid INTERRELATIONSHIPS genus Diplothelopsis, for example, the teeth originate near the ventral surface of the claw In this section we will first examine pre- (fig. 19) and hang below the claw itself (fig. vious suggestions that the closest relatives of 20). The pycnothelid type of tooth arrange- the microstigmatids may lie within the Par- ment is also found in at least some Diplurinae atropididae, Ctenizidae, or Dipluridae, and (fig. 18) and even Ctenizidae (fig. 17), where then present an alternative hypothesis of our the tooth origin does become more dorsal to- own. Hewitt's (1925) proposal of a paratro- ward the tip of the claw but is clearly ventral pidid relationship was based on similarities in at least the most proximal teeth. As the between Paratropis and Microstigmata in 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 9

FIGS. 33-36. Tarsal organ of leg I, dorsal views. 33. Microstigmata sp., 2000X. 34. Ministigmata minuta, new species, 6500x. 35. Pseudonemesia parva Caporiacco, 6250X. 36. P. kochalkai, new species, 9500x. spinneret structure, the "minutely scaly in- shorter than the median one in Microstig- tegument, more or less encrusted with grains mata, and the close spacing of the posterior of grit, and the peculiar thick hairs," al- median spinnerets mentioned by Hewitt though he concluded that "the relationship seems to be only a step involved in their re- of these two genera is not so very close, the duction (other genera in each family have ocular tubercle being globular in Paratropis, lost the posterior median spinnerets entire- paired tarsal claws unidentate, and the max- ly). The cuticle of Paratropis does not have illa has a conspicuous process at the anterior the scales of microstigmatids (fig. 21), and apical angle" (pp. 288-289). Although the although the characteristic paratropidid habit latter objections are not crucial (for they in- of encrusting the body with dirt does occur dicate only that Microstigmata lacks the au- in Microstigmata, it does not occur in Pseu- tapomorphies of Paratropis), Hewitt's cited donemesia or Ministigmata and is hence similarities are not convincing. The posterior presumably a parallel development. Para- lateral spinnerets of the two genera differ in tropis and Microstigmata do have similar en- having the apical segment almost twice as larged setae on the legs and abdomen (figs. long as the median one in Paratropis but 21, 22) that are also normally encrusted with lo AMERICAN MUSEUM NOVITATES NO. 2707

FIGS. 37-40. Trichobothrial base from tarsus I, dorsal views. 37. Microstigmata sp., 2100x. 38. Ministigmata minuta, new species, 6700X. 39. Pseudonemesia parva Caporiacco, 5000x. 40. P. ko- chalkai, new species, 6750x. dirt, but the setae of Microstigmata are just Discussion of possible microstigmatid re- as similar to the ordinary leg setae of other lationships with the Dipluridae, following microstigmatids (fig. 23). Hewitt's (1916) placement, is difficult. The If the sister group of the microstigmatids spiders formerly included in the Dipluridae were to lie within the Ctenizidae, as sug- are now placed in two families, the Hexa- gested by Caporiacco's (1955) placement, thelidae and Dipluridae, believed to be sister the absence of a rastellum would presumably groups (Raven, 1980b), and it is not certain be an apomorphic loss. This hypothesis whether Hewitt would have advocated a mi- would be parsimonious only if there are oth- crostigmatid relationship to both or to only er characters unique to microstigmatids and one of these families. As later workers (such some ctenizids (presumably the Nemesieae, as Roewer, 1942) have placed Microstig- as indicated by the two rows of teeth on their mata in the Diplurinae (presumably because paired tarsal claws; cf. Caporiacco's choice of the two rows of teeth on their paired tarsal of name for the Pseudonemesiinae). We claws), we will consider that hypothesis as know of no such characters. reflecting Hewitt's intent. Unfortunately, the 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 11

I FIGS. 41-44. Ministigmata minuta, new species, male, lateral views. 41, 42. Leg I, showing clasping spine; 41, 130x, 42, 560x. 43, 44. Palp; 43, 180x, 44, 320x.

Diplurinae is at present heterogeneous, and Similarly, a close relationship to the it is possible that some of the spiders cur- Brachytheleae or Anamini may be contra- rently placed in the group (such as the North- dicted by the presence in microstigmatids of ern Hemisphere "Brachytheleae" and the a serrula on the anterior surface of the palpal Australian "Anamini") do not belong there. coxae. The serrula is fully developed in Mi- For the purposes of this discussion, the term crostigmata (fig. 25), somewhat reduced in Diplurinae refers only to those genera, like Pseudonemesia (figs. 27, 28), and almost Diplura, with elongated posterior lateral completely lost in Ministigmata (fig. 25); a spinnerets and pseudosegmented tarsi in similar reduction of the serrula in small males. Placement of the microstigmatids species occurs in the Mecicobothriidae, within this restricted Diplurinae, or as their where Hexurella has a serrula much reduced sister group, is contradicted by their short from that of the genera containing larger posterior lateral spinnerets (the elongated species (Gertsch and Platnick, 1979, figs. 1- spinnerets group the Diplurinae with the oth- 4). A serrula is generally lacking in mygalo- er diplurids and the Hexathelidae and Me- morphs other than the Mecicobothriidae, cicobothriidae instead), and supported by no Hexathelidae, and Dipluridae and present in synapomorphies that we are aware of. those groups. However, it apparently does 12 AMERICAN MUSEUM NOVITATES NO. 2707

FIGS. 45-48. Pseudonemesia males, lateral views. 45. P. parva Caporiacco, palp, lOOx. 46-48. P. kochalkai, new species. 46. Leg I, showing clasping spine, 95x. 47. Palp, 80x. 48. Palp, 160x. not occur in at least some Brachytheleae and Pikelin, 1967); the unidentified specimens re- Anamini (i.e., "Diplurinae" with short pos- ported on previously may belong to the terior lateral spinnerets; although, contrary Brachytheleae or Anamini rather than Pyc- to the statement of Raven, 1980a, a serrula nothelidae. Hence the pycnothelids may does occur in Ixamatus) and hence argues prove to be dipluroids when the limits and for a closer relationship between microstig- affinities of the Diplurinae, Brachytheleae, matids and the Mecicobothriidae, Hexathel- Anamini, and Pycnothelidae can be investi- idae, and restricted Dipluridae than the gated in detail. Until then, the most we can Brachytheleae or Anamini. The only excep- suggest, following Platnick (1977) and Raven tions to the lack of a serrula in non-dipluroid (1980b), is that the Mecicobothriidae and the groups known to us occur in the Pycnothel- Hexathelidae plus Dipluridae (possibly mi- idae. Although Platnick (1977, p. 14) report- nus some current Diplurinae and/or plus ed that specimens of an unidentified pyc- some current Pycnothelidae) are sister nothelid genus lack a serrula, one has groups united by the elongated posterior lat- subsequently been found in the type species eral spinnerets, and further, that the Micro- of Pycnothele and in a species of Diploth- stigmatidae is the sister group of all three elopsis (and thus in both of the pycnothelid families, being united with them by the pres- subfamilies recognized by Schiapelli and de ence of a serrula. 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 13

FIGS. 49-54. 49-52. Pseudonemesia parva Caporiacco. 49. Body, dorsal view. 50. Body, ventral view. 51. Body, lateral view. 52. Carapace, anterior view. 53, 54. Spermathecae, dorsal views. 53. Ministigmata minuta, new species. 54. Pseudonemesia kochalkai, new species.

The tarsal organ morphology of microstig- INTRARELATIONSHIPS matids is compatible with this hypothesis. There is little doubt that the fundamental All examined mecicobothriids, hexathelids, dichotomy within the Microstigmatidae is and diplurids (other than Ixamatus; see be- between Microstigmata and Ministigmata, low) have a flattened tarsal organ bearing on the one hand, and Pseudonemesia on the numerous concentric ridges (Gertsch and other; these two groups are considered Platnick, 1979, figs. 17-32). The genera Mi- subfamilies below. The first two genera crostigmata and Ministigmata have a very agree in having the scales of the cuticle cov- different tarsal organ, in the form of a nar- ered with numerous digitiform pustules (figs. row, protruding lobe that extends consider- 8, 10) and in having lost the concentric ridges ably above the cuticle (figs. 29, 30, 33, 34). around the elevated portions of the tarsal However, Pseudonemesia has an interme- organ (figs. 33, 34). Similarly, the two diate form of tarsal organ in which only the species assigned to Pseudonemesia below central (receptor) area of the organ protrudes differ from Microstigmata and Ministigmata high above the cuticle, and is surrounded by in having corrugated trichobothrial bases the concentric ridges typical of diplurids, (figs. 37-40); as primitive dipluroids (Meci- hexathelids, and mecicobothriids (figs. 31, cobothriidae and Hexathelidae) have smooth 32, 35, 36). Hence the microstigmatids seem trichobothrial bases (Raven, 1980b), that is merely to have an apomorphic form of the presumably the plesiomorphic state of the type of tarsal organ found in their putative character for the Microstigmatidae. The two sister group. A similar protruding tarsal or- Pseudonemesia species also have a unique gan may have developed in a parallel fashion type of serrula morphology (figs. 27, 28) in in the diplurine genus Ixamatus (Raven, which the teeth of the serrula are widely sep- 1980a, figs. 11, 12) and a closely related un- arated and greatly flattened, and a peculiarly described genus. elevated pars thoracica (fig. 51). 14 AMERICAN MUSEUM NOVITATES NO. 2707

If the reduced serrula of Ministigmata (fig. Koestler with the scanning electron micro- 26) were a modified form of the type of ser- scope. We thank Mr. B. Campbell, Dr. V. rula found in Pseudonemesia, the character Davies, and Dr. B. Y. Main for valuable dis- would argue against the dichotomy proposed cussions, and Drs. F. A. Coyle, R. R. Fors- above, but there seems to be little in the de- ter, and W. J. Gertsch for reviewing drafts tails of the morphology to support that view. of the manuscript. The only other character that might contra- dict the grouping adopted here is the spin- MICROSTIGMATIDAE ROEWER neret number; the posterior median spinner- ets have been lost in both Pseudonemesia Microstigmateae Roewer, 1942, p. 194. and Ministigmata. Since the same loss has Pseudonemesiinae Caporiacco, 1955, p. 265. also occurred in the families Paratropididae NEW SYNONYMY. (Anisaspis and Anisaspoides), Ctenizidae DIAGNOSIS: Microstigmatids can be easily (one species of Nemesia), recognized by the small, oval openings of the (Diplothele and related taxa), and Pycno- book-lungs (figs. 1, 50), the scaly cuticle thelidae (Diplothelopsis), it is not unrea- (figs. 5-10), and the two rows of dorsally sonable to assume a parallel loss of those originating teeth on the paired tarsal claws spinnerets in the two genera of tiny micro- (figs. 11-14). They can be distinguished from stigmatids. the other mygalomorph families as follows: Pseudonemesia parva and P. kochalkai from the Theraphosidae and Barychelidae by differ in modifications of the male tibia I (a the presence of three tarsal claws and the character that frequently provides good in- absence of tarsal claw tufts, from the Pyc- dications of roughly generic-level affinities in nothelidae by the absence of tarsal scopulae, mygalomorphs), and we suspect that they from the Paratropididae and by the will be placed in separate genera when ad- presence of two rows of teeth on the paired ditional species are discovered. Description tarsal claws, from the Ctenizidae, Actino- of a new monotypic genus for P. kochalkai, podidae, and by the absence however, seems premature at this time. of a cheliceral rastellum, from the Mecico- Also, no detailed discussion of Microstig- bothriidae, Hexathelidae, and Dipluridae mata is provided here because there are un- (except "Brachytheleae" and "Anamini") described species of that genus in African by the short posterior lateral spinnerets, collections. from the "Brachytheleae" and "Anamini" by the presence of a serrula and/or the ab- ACKNOWLEDGMENTS sence of tarsal scopulae, and from the Atyp- We are indebted to Drs. M. Hubert of the idae by the absence of the anterior lateral Museum National d'Histoire Naturelle for spinnerets and lobes on the palpal coxae. the loan of the types of Accola lucifuga Si- DESCRIPTION: Small to tiny mygalomorph mon (among which the males of P. parva spiders. Carapace oval, with short trans- were found), B. Lamoral of the Natal Mu- verse thoracic groove and compact group of seum for the loan of African Microstigmata, eight eyes in two rows. Chelicerae paraxial, and R. Martinez of the Museo de Biologia, geniculate, with promarginal row of teeth, Universidad Central de Venezuela for lend- with or without mesal teeth, without rastel- ing the holotype of P. parva. Mr. J. A. Ko- lum. Palpal coxae longer than wide, without chalka of the University of Florida kindly anterior lobes, with or without cuspules, donated the material of P. kochalkai, and with serrula (slightly reduced in Pseudone- Dr. W. L. Brown, Jr., of Cornell University mesia, almost completely lost in Ministig- provided the material of M. minuta and de- mata); female palp with claw bearing single tails on its type locality. At the American row of teeth. Labium wider than long, with Museum of Natural History, Dr. P. Wygod- or without cuspules. Sternum cordate, with zinsky assisted with translations, Dr. M. U. or without visible sigilla. Tarsi with three Shadab with illustrations, and Mr. R. J. claws, paired claws with two rows of dor- 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 15 sally originating teeth, unpaired claws long, duced overlapping ridge. Tarsi without bare; tarsal organ elevated, with or without whorled seta at base of claws. Cuticle with surrounding concentric ridges; trichobothria digitiform pustules. Abdomen without scu- in two rows on tibiae, single row on meta- tum, usually encrusted with dirt. Four spin- tarsi and tarsi; trichobothrial bases smooth nerets, posterior medians tiny, one-segment- or corrugated; claw tufts and scopulae ab- ed, closely spaced. Males with incrassate sent. Cuticle scaly, with or without digiti- prolateroventral spine at apex of tibia I. form pustules. Abdomen with or without ter- INCLUDED SPECIES: M. geophilum (Hew- gite-like anterior scutum, with book-lung itt), M. zuluense (Lawrence), M. iongipes apertures very small, oval; spinnerets four (Lawrence). or two, posterior laterals very short, three- DISTRIBUTION: The genus is known only segmented, with apical segment shorter than from the Cape Province and Natal, South median, coniform. Males with pyriform pal- Africa, and found under stones in damp bush pal bulb, with or without incrassate spine on and forest (Hewitt, 1916, 1925). tibia I. MINISTIGMATA, NEW GENUS MICROSTIGMATINAE ROEWER TYPE SPECIES: Ministigmata minuta, new Microstigmateae Roewer, 1942, p. 194. species. DIAGNOSIS: Microstigmatines can be dis- ETYMOLOGY: The generic name is from tinguished from pseudonemesiines by the the Latin minimus (smallest) and stigma (a presence of digitiform cuticular pustules cut), referring to the scarcely visible book- (figs. 7-10) and smooth trichobothrial bases lung openings, and is feminine in gender. (figs. 37, 38), and by the absence of concen- DIAGNOSIS: Ministigmata can be distin- tric ridges surrounding the tarsal organ (figs. guished from Microstigmata by the presence 29, 30, 33, 34). of only two spinnerets. The peculiar whorled INCLUDED GENERA: Microstigmata and seta found at the base of the tarsal claws (fig. Ministigmata. 24) is also diagnostic. DISTRIBUTION: Known only from South DESCRIPTION: Tiny mygalomorph spiders. Africa (Microstigmata) and Brazil (Ministig- Thoracic groove very narrow, straight. Che- mata). licerae with mesal denticles. Palpal coxae with, labium without cuspules. Sternum MICROSTIGMATA STRAND without visible sigilla. Tarsal organ without concentric ridges. Trichobothrial bases Microstigma Hewitt, 1916, p. 206 (type species by monotypy Microstigma geophilum Hewitt); smooth, with well-developed overlapping 1925, p. 286. Lawrence, 1938, p. 459. Bonnet, ridge. Tarsi with whorled seta at base of 1957, p. 2906. claws. Cuticle with digitiform pustules. Ab- Microstigmata Strand, 1932, p. 142 (nomen no- domen with vaguely limited, shiny, anterior vum for Microstigma Hewitt, preoccupied in scutum at base, not encrusted with dirt. Two the Odonata by Microstigma Rambus, 1842). spinnerets. Males with incrassate prolater- Roewer, 1942, p. 194. oventral spine at apex of tibia I. DIAGNOSIS: Microstigmata can be distin- guished from Ministigmata by the presence Ministigmata minuta, new species of four spinnerets. Figures 7, 8, 12, 15, 23, 24, 26, 30, 34, 38, 41-44, DESCRIPTION: Small mygalomorph spi- 53 ders. Thoracic groove slightly recurved, de- TYPES: Male holotype and female paratype pressed. Chelicerae with mesal denticles. from Berlese sample of leaf litter taken in Palpal coxae and labium usually with cus- shady rainforest along the Rio Negro at Pon- pules. Sternum with one to three pairs of sig- ta Negra, Manaus, Amazonas, Brazil (Sep- illa visible. Tarsal organ without concentric tember 1, 1962; W. L. Brown, Jr.), deposited ridges. Trichobothrial bases smooth, with re- in the American Museum of Natural History. 16 AMERICAN MUSEUM NOVITATES NO. 2707

ETYMOLOGY: The specific name is from coxae III and IV with incipient hooked distal the Latin minutus (tiny). processes retrolaterally. Spination (no spines DIAGNOSIS: With the characters of the ge- on tarsi): leg I, femur d4, patella 0, tibia v2 nus. (plus clasping spine), metatarsus v2; leg II, MALE: Total length, including chelicerae, femur d4, patella 0, tibia v2, metatarsus v2; 1.80. Carapace and legs uniformly brownish leg III, femur d4, patella dl, p2, tibia d3, pl, yellow, chelicerae paler; underside of ceph- v4, rl, metatarsus p3, v3, r2; leg IV, femur alothorax concolorous. Dorsum of abdomen d3, pl, r2, patella pl, rl, tibia d4, pl, v3, r2, yellow with irregular median purplish brown metatarsus p3, v2, r3. Paired tarsal claws mottling and shiny brown scutum above with two rows, each of five to seven teeth. base; sides and venter uniformly yellow. Four to five trichobothria in irregular row on Carapace 0.88 long, 0.69 wide, sloping metatarsi and tarsi, two rows of four to five evenly from thoracic groove in all directions each on tibiae. except anteriorly on medially domed caput, glabrous, with two rows each of four or five I II III IV Palp posteriorly directed bristles reaching from Femur 0.56 0.56 0.46 0.71 0.33 Patella 0.35 0.36 0.29 0.39 0.25 lateral eyes toward thoracic groove, two Tibia 0.34 0.30 0.28 0.50 0.25 bristles at posterolateral corners, two bris- Metatarsus 0.31 0.31 0.39 0.68 tles lateral of eyes, one long recurved bristle Tarsus 0.26 0.26 0.30 0.39 0.15 between anterior median eyes, and two long Total 1.82 1.79 1.72 2.67 0.98 bristles, with apices touching, on clypeal edge. Thoracic groove a short, straight, Palp (figs. 43, 44) with incrassate tibia and transverse slit situated back two-thirds of tarsus and elongate, distally twisted embo- carapace length, occupying only one-tenth of lus; tibia with two dorsal spines. carapace width at that point. Abdomen 0.75 long, 0.44 wide, glabrous Eight eyes on low tubercle occupying but with long, erect, clavate bristles; poste- about one-third of front width. Ratio of eyes, rior book-lung covers each marked by long anterior lateral: anterior median: posterior erect bristle. Three-segmented posterior lat- lateral: posterior median, 4:2:3:2. Anterior eral spinnerets with basal, median, and api- row very slightly narrower than posterior, cal segments 0.05, 0.06, 0.03 long, respec- strongly recurved from above; medians sep- tively. arated by their radius, by half their radius FEMALE: As in male, except as noted. To- from laterals. Posterior row strongly re- tal length, including chelicerae, 2.00. Cara- curved; medians separated by three times pace, legs, and chelicerae uniformly yellow- their diameter, by half their radius from lat- ish. Brown mottling of abdominal dorsum erals. Median ocular quadrangle wider than forming numerous pigmentless spots. Cara- long (9/6), narrowed in front (9/5). Lateral pace 0.78 long, 0.65 wide. Eye group occu- eyes of each side separated by half their ra- pying almost one-half of front width. Ratio dius. of eyes, anterior lateral: anterior median: Sternum 0.46 long, 0.46 wide, domed, with posterior lateral: posterior median, 4:2:3:3. bristles on margin. Labium 0.06 long, 0.18 Anterior medians separated by half their ra- wide, quadrangular, without cuspules, with dius. Median ocular quadrangle wider than five bristles anteriorly. Palpal coxae 0.25 long (4/3), narrowed in front (4/3). Sternum long, 0.14 wide, with two or three cuspules 0.46 long, 0.31 wide. Labium 0.05 long, 0.14 and attenuate bristles. Chelicerae short, pro- wide. Palpal coxae 0.23 long, 0.15 wide, with margin with five to seven teeth, mesally with one or two cuspules. Cheliceral promargin about four teeth; fang long, slender. with five teeth, mesally with eight teeth. Leg formula 4123. Legs glabrous but with Coxae III and IV with small hooked distal erect attenuate and bluntly tipped bristles; protuberance retrolaterally. Spination: leg I, femur II slightly incrassate; tibia I with single tibia v2, metatarsus 0; leg II, patella dl, tibia apical incrassate clasping spine (figs. 41, 42); dl, v2, metatarsus pl, v2; leg III, femur d3, 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 17 patella d2, p2, rl, tibia d3, pl, v2, rl, meta- Thoracic groove slightly recurved. Chelic- tarsus d2, p2, v3, r2; leg IV, femur d2, patella erae with promarginal teeth only. Palpal cox- dl, p1, ri, tibia d3, p1, v4, ri, metatarsus d2, ae with or without, labium without cuspules. p2, v3, r3; palp, femur d2, patella 0, tibia dl, Sternum without visible sigilla. Tarsal organ tarsus 0. with concentric ridges. Trichobothrial bases corrugated. Tarsi without whorled seta at II III IV Palp Femur 0.56 0.44 0.39 0.60 0.34 base of claws. Cuticle without digitiform Patella 0.38 0.30 0.28 0.34 0.28 pustules. Abdomen with vaguely limited, Tibia 0.31 0.28 0.24 0.44 0.19 shiny, anterior scutum at base, not encrusted Metatarsus 0.28 0.26 0.31 0.50 with dirt. Two spinnerets. Males with or Tarsus 0.19 0.20 0.25 0.34 0.24 without incrassate spine on tibia I. Total 1.72 1.48 1.47 2.22 1.05 Pseudonemesia parva Caporiacco Abdomen 1.00 long, 0.63 wide. Spinnerets Figures 5, 13, 27, 31, 35, 45, 49-52 with basal, median, and apical segments Pseudonemesia parva Caporiacco, 1955, p. 266 0.06, 0.05, 0.02 long, respectively. Sperma- (female holotype from El Junquito, Distrito thecae two, elongate, medially directed, ba- Federal, Venezuela, in Museo de Biologia, Uni- sally expanded (fig. 53). versidad Central de Venezuela, examined). MATERIAL EXAMINED: Two females and one juvenile taken with the types in a de- DIAGNOSIS: Male of P. parva can be easily graded forest just north of a swimming beach distinguished from P. kochalkai by the ab- and back from low, red cliffs lining the river sence of an incrassate spine on tibia I, fe- at that point. The type locality was revisited males by the absence of cuspules on the pal- by Dr. W. L. Brown, Jr., in 1971, and was pal coxae. much modified as the beach has become a MALE: Total length, including chelicerae, resort and even more of the forest has been 2.74; body as in figures 49-52. Carapace tan, chopped. with irregular darker pigmentation on inter- strial ridges and caput; chelicerae, underside PSEUDONEMESIINAE CAPORIACCO of cephalothorax, and legs pale tan. Dorsum of abdomen light brown with pale flanks and Pseudonemesiinae Caporiacco, 1955, p. 265. pale, irregularly defined anteromedian scu- DIAGNOSIS: Pseudonemesiines can be dis- tum, venter entirely pale yellow. tinguished from microstigmatines by the ab- Carapace 1.42 long, 1.20 wide, sloping sence of digitiform cuticular pustules (figs. down on all sides from thoracic groove; gla- 5, 6) and the presence of corrugated tricho- brous except for five bristles in posterior bothrial bases (figs. 39, 40) and concentric striae, one pair of foveal bristles, four or five ridges surrounding the tarsal organ (figs. 31, bristles on anterior and posterior cephalic 32, 35, 36). margins, and four bristles in front of eyes. INCLUDED GENERA: Pseudonemesia. Thoracic groove short, shallow, slightly re- DISTRIBUTION: Known only from Vene- curved line situated back four-sevenths of zuela (P. parva) and Colombia (P. kochal- carapace length, occupying two-fifteenths of kai). carapace width at that point. Eight eyes on distinctly raised tubercle oc- Pseudonemesia Caporiacco cupying about one-half of front width. Ratio of eyes, anterior lateral: anterior median: Pseudonemesia Caporiacco, 1955, p. 266 (type posterior lateral: posterior median, 9:5:9:6. species by original designation Pseudonemesia Anterior row slightly narrower than poste- parva Caporiacco). rior row, slightly recurved from above; me- DIAGNOSIS: With the characters of the dians separated by slightly more than their subfamily. radius, slightly closer to laterals. Posterior DESCRIHrION: Tiny mygalomorph spiders. row strongly recurved, medians separated by 18 AMERICAN MUSEUM NOVITATES NO. 2707 twice their diameter, by their radius from lat- specimen is too fragile to dissect safely. It erals. Median ocular quadrangle wider than agrees with the males described above in the long (3/2), narrowed in front (3/2). Lateral structure of the book-lung openings, cuticle, eyes of each side separated by half their ra- tarsal claws, serrula, tarsal organ, and trich- dius. obothrial bases. Since the males were col- Sternum 0.80 long, 0.70 wide, smooth, lected in an area very close to the type lo- with steeply sloping lateral margins, without cality, we have no hesitation in considering bristles. Labium 0.06 long, 0.28 wide, ante- the specimens conspecific. riorly excavate, separated from sternum by MATERIAL EXAMINED: The holotype, plus depression, without cuspules, with eight two males found with the syntypes of Accola bristles on anterior margin. Palpal coxae 0.62 lucifuga Simon, presumably taken with them long, 0.30 wide, without cuspules, with at Colonia Tovar, Aragua, Venezuela, and about five darkened regions at bases of sco- housed in the Museum National d'Histoire pular hairs. Chelicerae short, rounded, Naturelle. Colonia Tovar is at latitude 100 25' clothed with about 20 widely spaced bristles; N, longitude 670 17' W; El Junquito is nearby promargin with six to eight teeth; fang long, at latitude 10° 28' N, longitude 670 05' W. curved, rising upwards apically. Leg formula 4132. Legs glabrous but with Pseudonemesia kochalkai, new species erect bristles; femora I and II incrassate but Figures 6, 14, 16, 28, 32, 36, 40, 46-48, 54 otherwise without modifications. Spination (no spines on tarsi): leg I, femur d5, patella TYPES: Male holotype and female paratype 0, tibia v5, metatarsus v4; leg II, femur d5, sifted from leaf litter at an elevation of 960 patella 0, tibia v6, metatarsus p1, v6; leg III, m. at San Pedro, Sierra Nevada de Santa femur d5, p3, r3, patella pl, rl, tibia d2, pl, Marta, Magdalena, Colombia (May 19, 1975; v4, r2, metatarsus p2, v4, r2; leg IV, femur J. A. Kochalka), deposited in the American d5, rl, patella pl, rl, tibia d3, p2, v3, r3, Museum of Natural History courtesy of Mr. metatarsus p3, v4, r3. Paired tarsal claws Kochalka. with two rows, each of two to five teeth. ETYMOLOGY: The specific name is a pa- Trichobothria as in M. minuta. tronym in honor of the collector of the type specimens. II III IV Palp DIAGNOSIS: Males of P. kochalkai can be Femur 1.08 0.96 0.92 1.24 0.64 easily distinguished from those of P. parva Patella 0.68 0.56 0.48 0.64 0.44 by the large spine on tibia I (fig. 46), females Tibia 0.72 0.56 0.60 0.84 0.52 by the presence of cuspules on the palpal Metatarsus 0.64 0.64 0.68 1.16 coxae. Tarsus 0.48 0.44 0.56 0.72 0.28 MALE: Total length, including chelicerae, Total 3.60 3.16 3.24 4.60 1.88 3.08. Carapace brown with irregular darker Palp (fig. 45) with normal tibia and very areas on median caput and interstrial ridges; short embolus; femur with four dorsal and underside of cephalothorax and legs lighter one prolateral, tibia with four ventral, tarsus brown. Dorsum of abdomen dark brown with with one ventral and two apical spines. paler anterior areas covered with shiny scu- Abdomen 1.56 long, 0.94 wide, glabrous tum; venter white with irregular brown mot- but with erect bristles; posterior book-lungs tling laterally. widely separated, in anterior half of abdo- Carapace 1.50 long, 1.20 wide, sloping men. Three-segmented posterior lateral spin- down on all sides from thoracic groove but nerets with basal, median, and apical seg- less so anteriorly; glabrous except for sev- ments 0.12, 0.06, 0.06 long, respectively. eral fine bristles in posterior striae and on FEMALE: Described by Caporiacco (1955), cephalic margin, one pair of foveal bristles, who considered the holotype to be a juve- and two bristles in front of eye group. Tho- nile. Comparison with other species indi- racic groove short, shallow, slightly re- cates that it is probably an adult, but the curved line positioned as in P. parva. 1981 RAVEN AND PLATNICK: MICROSTIGMATIDAE 19

Eight eyes on raised tubercle occupying one ventral, tarsus with one ventral and two almost two-thirds of front width. Ratio of apical spines. eyes, anterior lateral: anterior median: pos- Abdomen 1.34 long, 0.84 wide, glabrous terior lateral: posterior median, 8:5:6:4. An- but with erect bristles; posterior book-lung terior row slightly narrower than posterior apertures very small, round, anterior pair row, procurved from above; medians sepa- obscured. Three-segmented posterior lateral rated by slightly more than their radius, spinnerets with basal, median, and apical slightly closer to laterals. Posterior row re- segments 0.13, 0.10, 0.04 long, respectively. curved, medians separated by twice their di- FEMALE: As in male, except as noted. To- ameter, by their radius from laterals. Median tal length, including chelicerae, 2.90. Cara- ocular quadrangle wider than long (15/9), pace 1.34 long, 1.10 wide, with few bristles narrowed in front (15/11). Lateral eyes of on posterior margin, row of short erect bris- each side separated by half their radius. tles from lateral of eyes to thoracic groove, Sternum 0.78 long, 0.66 wide, domed, with two bristles on clypeal edge, and one re- few bristles at margins. Labium 0.08 long, curved bristle between posterior median 0.21 wide, anteriorly excavate, separated eyes. Thoracic groove straight. Ratio of from sternum by depression, without cus- eyes, anterior lateral: anterior median: pos- pules, with about eight bristles anteriorly. terior lateral: posterior median, 4:1:2:2. An- Palpal coxae 0.44 long, 0.30 wide, with three terior eye row straight from above, medians cuspules on inner edge. Chelicerae clothed separated by twice their diameter, by their only with about 15 widely spaced bristles, radius from laterals. Median ocular quadran- promargin with seven teeth; fang as in P. gle wider than long (14/7), narrowed in front parva. (14/10). Sternum 0.64 long-, 0.69 wide. La- Leg formula 4132. Legs glabrous but with bium 0.06 long, 0.25 wide. Palpal coxae 0.38 erect scattered bristles; femora I and II in- long, 0.31 wide, with three or four cuspules. crassate; tibia I with very long incrassate Chelicerae clothed with 15-20 fine bristles, spine at half its length, raised on apophysis promargin with six teeth. Leg formula 4123, distal of which segment is excavate with ret- legs unmodified. Spination: leg I, femur d5, rolateroventral thornlike spine (fig. 46). Spi- tibia v3, metatarsus v4; leg II, femur d6, pa- nation (no spines on tarsi): leg I, femur d6, tella 0, tibia v4, metatarsus v3; leg III, femur patella 0, tibia v2 (plus clasping spine), meta- d4, p2, tibia d2, pl, v3, metatarsus dl, p2, tarsus v2; leg II, femur d5, patella pl, tibia v5, r2; leg IV, femur d5, tibia dl, p2, v5, r3, v5, metatarsus v4; leg III, femur d3, p3, r3, metatarsus p3, v6, r2; palp, femur d5, patella patella pl, ri, tibia dl, p1, v6, ri, metatarsus 0, tibia v5, tarsus p1. Paired tarsal claws with dl, p1, v6, r2; leg IV, femur d4, ri, patella two rows, each of six teeth on legs I and II, p1, rl, tibia dl, p2, v5, r2, metatarsus p4, v6, three or four teeth on legs III and IV. r3. Paired tarsal claws with two rows, each of five to six teeth. Trichobothria as in M. I II III IV Palp minuta. Femur 1.00 0.84 0.73 1.00 0.63 Patella 0.63 0.50 0.46 0.53 0.49 I II III IV Palp Tibia 0.63 0.50 0.48 0.80 0.45 Femur 1.06 1.00 0.84 1.23 0.60 Metatarsus 0.51 0.50 0.59 0.88 Patella 0.70 0.56 0.46 0.64 0.45 Tarsus 0.38 0.41 0.40 0.48 0.44 Tibia 0.75 0.53 0.56 1.13 0.45 Total 3.15 2.75 2.66 3.69 2.01 Metatarsus 0.68 0.59 0.84 1.25 Tarsus 0.43 0.49 0.51 0.68 0.33 Palp with claw bearing single row of six Total 3.62 3.17 3.21 4.93 1.83 teeth. Abdomen 1.20 long, 0.64 wide, with low white mound and central bristle repre- Palp (figs. 47, 48) with normal tibia, short, senting expected position of posterior medi- blunt embolus, and oval bulb situated sub- an spinnerets; three-segmented posterior lat- apically on tarsus; tibia with one dorsal and eral spinnerets with basal, median, and 20 2AMERICAN MUSEUM NOVITATES NO. 2707 apical segments 0.18, 0.10, 0.04 long, re- analysis, with notes on the spectively. Two bifid spermathecae (fig. 54). (Arachnida, Araneae). Amer. Mus. EXAMINED: Three females and Novitates, no. 2627, pp. 1-23, figs. 1- MATERIAL 31. one juvenile taken with the type specimens. Raven, Robert J. 1980a. The Australian mygalomorph spider ge- LITERATURE CITED nus Ixamatus Simon (Dipluridae: Di- plurinae) and its affinities. Bull. British Bonnet, Pierre Soc., vol. 5, pp. 43-49, figs. 1957. Bibliographia araneorum. Toulouse, Arachnol. vol. 2, pt. 3, pp. 1927-3026. 1-14. Caporiacco, Lodovico D. 1980b. The evolution and biogeography of the 1955. Estudios sobre los aracnidos de Vene- mygalomorph spider family Hexatheli- zuela, 2. Araneae. Acta Biol. Vene- dae (Araneae, ). Jour. Ar- vol. 8, pp. 251-266, figs. 1-4. zuelica, vol. 1, pp. 265-448, figs. 1-83. achnol., Roewer, Carl F. Gertsch, Willis J., and Norman I. Platnick 1979. A revision of the spider family Meci- 1942. Katalog der Araneae. Bremen, vol. 1, Mygalomor- 1040 pp. cobothriidae (Araneae, Berta S. Gerschman de phae). Amer. Mus. Novitates, no. 2687, Schiapelli, Rita D., and pp. 1-32, figs. 1-91. Pikelin 1967. La familia Pycnothelidae (Chamberlin, Hewitt, John Se- 1916. Descriptions of new South African spi- 1917) (Araneae-Mygalomorphae). ders. Ann. Transvaal Mus., vol. 5, pp. gundas Jornadas Entomoepidemiologi- cas Argentinas, vol. 1, pp. 45-64, figs. 180-213, figs. 1-11. 1-33. 1925. Descriptions of some African Arach- Rec. Albany Mus., vol. 3, pp. Simon, Eugene nida. 1892. Histoire naturelle des Araignees. Paris, 277-299, figs. 1-3. 1-215. Lawrence, Reginald F. vol. 1, pt. 1, pp. 1-256, figs. of spiders from Natal and Strand, Embrik 1938. A collection et Zululand. Ann. Natal Mus., vol. 8, pp. 1932. Miscellanea nomenclatoria zoologica 455-524, figs. 1-40. paleontologica, III. Folia Zool. Hydro- biol., vol. 4, pp. 133-147. Platnick, Norman I. 1977. The hypochiloid spiders: A cladistic