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Fall 12-2-1953 The Altitudinal Distribution of in Boulder County, Colorado Fred Harold Tschirley University of Colorado Boulder

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Recommended Citation Tschirley, Fred Harold, "The Altitudinal Distribution of Spiders in Boulder County, Colorado" (1953). University Libraries Digitized Theses 189x-20xx. 19. http://scholar.colorado.edu/print_theses/19

This Dissertation is brought to you for free and open access by University Libraries at CU Scholar. It has been accepted for inclusion in University Libraries Digitized Theses 189x-20xx by an authorized administrator of CU Scholar. For more information, please contact [email protected]. THE ALTITUDINAL DISTRIBUTION OF SPIDERS IN BOULDER COUNTY, COLORADO

by Fred Harold Tschirley B.A., University of Colorado, 1951

A Thesis submitted to the Faculty of the Graduate School of the University of Colorado in partial fulfillment of the requirements for the degree Master of Arts Department of Biology 1954 This Thesis for the M.A. degree by

Fred Harold Tschirley

has been approved for the

Department of

Biology

by Tschirley, Fred Harold (M.A., Biology: Zoology)

The Altitudinal Distribution of Spiders in Boulder County, Colorado* Thesis directed by Associate Professor Robert E. Gregg

Preliminary collections were made in the summer of 1951 in an effort to determine whether altitudinal zonation exists among spiders. These collections were continued and completed in the summer of 1952. A total of 1212 determined specimens represent the basis for this thesis.

Despite the fact that collections were made during two summers, the number of specimens obtained for some species was very small, making definite zonal restriction difficult. On the basis of the entire collection, however, altitudinal zonation was quite evident. Sixty-nine of the total 101 species occurred in only one zone. That such a high proportion of species are unizonal is significant and can only be interpreted as indicating that spiders do conform, at least to some extent, to altitudinal zones. The results of this study should not be accepted as conclusive, however. Intensive and extensive collecting will be necessary to validate the present data.

On the basis of field experience three species were found to be common and characteristic of certain habitats. Pardosa sternalis can always be found in meadows of the plains zone during the summer months. Pardosa yavapa is also found in meadows but prefers the foothills and montane zones. utahana is easily found in buildings in the plains zone. Three female specimens representing the genera Allotheridion, Paraphidippus and Haplodrassus have not been identified. They are probably new species and will be described and published after ascertaining that they have not been previously recorded.

This abstract of about 240 words is approved as to form and content. I recommend its publication. TABLE OF CONTENTS

Page Introduction ...... 1 History ...... 2 Procedure ...... 6 Discussion ...... 15 Summary ...... 25 Selective bibliography ...... 26 Appendix ...... 31* THE ALTITUDINAL DISTRIBUTION OF SPIDERS IN BOULDER COUNT!, COLORADO

INTRODUCTION AND ACKNOWLEDGEMENT

Hie altitudinal distribution of has commanded the attention of investigators for many years* No attempt has been made, however, to determine whether an altitudinal zonation exists among spiders. Denis (1950) has done a great deal of collecting at high altitudes, but has made no attempt to correlate species occurrence with altitudinal zones*

An interest in altitudinal distribution was first developed in 1950 and this interest was increased with the knowledge that spiders had been a neglected group in Boulder County* The purpose of this thesis, therefore, is to determine whether an altitudinal zonation exists for spiders, and also to supplement the collection at the University of Colorado Museum.

I should like to express my sincere appreciation to Dr. Willis J* Gertsch of the American Museum of Natural History and to Dr* Donald C* Lowrie of the University of Idaho, Moscow, Idaho for identifying the species collected for this study. Thanks are also due Dr. Robert E. Gregg, University of Colorado, for his supervision, helpful suggestions and honest criticism. To all members of the Department of Biology I am indebted for a good foundation in the 2

complex and ever widening field of biology* Many friends, too numerous to mention, have aided me in the collection of specimens*

HISTORY

The distribution of plant and life has been of interest and has occuppied the efforts of many workers for many years* Organisms are not uniformly and universally distributed. To learn the patterns and reasons for inequitable distribution both stim­ ulates interest and presents a challenge. It is not surprising, therefore, that many differences of opinion have arisen regarding the restriction of various groups to a particular zone or zones. Merriam (1892) was the first worker to establish life zones which were distinct and, on the whole, acceptable* These zones were Tropical, Lower Sonoran, Upper Sonoran, Transition, Canadian, Hudsonian and Arctic-Alpine* They are based primarily on the latitudinal distribution of North American mammals resulting from environmental temperature differences. Since average temperature decreases with increasing altitude as it does with increasing latitude, we find that there is generally an altitudinal as well as latitudinal distribution of plants and animals. There are some workers, however, who reject the principle of zonation— at least for certain groups. Folsom and Wardle (193k) state that insects are independent of minor climatic differences and therefore they cannot be expected to exhibit a distribution based on Merriam1 s life zones. They maintain, on the other hand, 3 that North American insects exhibit a distribution based on the vegetation zones derived from rainfall patterns. Chopard (19U5) studying the Orthopteroid fauna of mountains in the Cameroon, states that there is little difference in the fauna between 1800 and 3000 meters and that of the adjacent low­ lands. Leng (1912) finds a similar situation in regard to the distribution of Cicindelidae in eastern North America. He states that, HTo attempt to define zones or regions for such a group is a hopeless task for scarcely any barrier is effective for all species, all the time." In contradiction to the opinions expressed by these workers there is a considerable body of research which upholds the prin­ ciple of geographic and altitudinal distribution. A great deal of this work has been done in the Rocky Mountains with much of it being centered in Colorado. Famaley (1907) has established the plant zones in the Rocky Mountains of Colorado. Ihey are essentially the same as those of Merriam but are termed plains, foothills, montane, sub-alpine and alpine. In Tables I, II and III these zones are designated respectively as P, F, M, S, and A. The zones established by Ramaley will be used throughout this thesis. Dodds and Hisaw (1925)> in an early study, list 100 species of aquatic insects which show definite altitudinal zonation. This zonation is not due to altitude, per se, but supposedly results primarily from temperature differences. k

Alexander (1951) gives a list of species of Acrididae known from above timberline in Colorado* He makes a distinction, how­ ever, between resident alpine species, completing their life cycles above timberline, and species of accidental occurrence which presumably reach the alpine zone by rising diurnal air currents* Of 28 species and sub-species collected above timberline in Colorado only eleven were considered to be resident alpine species. Alexander (19U0), studying the entomology of the Presidential Range of New Hampshire states that many insects found at high altitudes have been carried up by rising air currentso

In some cases altitudinal distribution exists but not in accordance with the five zones established by Ramaley. Dodds (1919, 1920), in his study of the Entomostraca in the Rocky Mountains of Colorado concludes that there are only three dis­ tinct zones. These zones are plains, montane and alpine. A similar situation exists with regard to the ants. Gregg (191*7) states that Colorado ants can be divided into three groups representing the plains, coniferous forest and alpine zones. There may possibly be a transition group*

Pennak (19lil) has found a limnological distribution somewhat different* Four zones are established for aquatic species occurring in lakes at various altitudes in Colorado* The zones are plains, foothills, montane and alpine* Haubold (1951), studying the distribution of Carabidae (Coleoptera) in Boulder County, Colorado states: There is definite evidence that vertical zonation among the Carabidae does exist in Boulder County as indicated by the fact that twenty-two of the thirty-four most common species in the collection were found in only one zone. Haubold further states that the occurrence of nineteen euryzonal forms does not disprove zonation. Their presence in more than one zone was attributed to the presence of similar environmental conditions. * Zonal distribution as such has not been attempted in any area for spiders. There is evidence both for and against such a pattern. In opposition to the theory of zonal distribution the work of Glick (1939) offers convincing testimony. This study consisted of a collection of insects, mites and spiders collected in a trap mounted on an airplane. Collections were made at various altitudes. The data taken from this study showed that spiders were collected at elevations ranging from twenty to 15,000'. To be sure, only one specimen was collected at 15,000', but collections were made at 1000' intervals from 1000 to 15,000' and in this altitudinal range 73U specimens were recorded. A total of 1U61 spiders, sixty of them taken at night, were collected. Specimens from fifteen families were included in the total collection. This study did not show how far spiders might be carried, however. To establish that, Comstock (19l*0) states that showers of gossamer have been met by ships at sea hundreds of miles from land. Both of the above accounts indicate that any attempt to plot the altitudinal distrib­ ution of spiders is open to much adverse criticism. As mentioned 6

previously, however, there is also evidence that geographic dis­ tribution of spiders does exist. There are species which show a distinct boreal distribution. This is evidenced by a comparison of high altitude species collected in Colorado with the same species collected at greater latitudes. It is difficult and at times impossible to map the altitudinal distribution of a species from published records. In many cases the collection site is indicated by giving only the state or the county. Obviously it is not possible to ascertain specific elevations from such data. There are a number of works, however, which give the species of spiders for a particular area. From such records it is possible to plot, for instance, a boreal distribution.

PROCEDURE

Boulder County lies in the north-central part of Colorado immediately west of the 105th meridian. The fortieth parallel of north latitude crosses the southern part of the county. Topographically, Boulder County is ideally suited to a study of altitudinal zonation. Elevations range from a maximum of lit, 255' on Longs Peak to a minimum of 5000’ on the plains to the east. Since the county measures only thirty-five miles from east to west there is a marked change of elevation, and consequently climatic conditions change also, within a relatively small area. A total of eight collection stations at 1000’ intervals are indicated on the map in Figure 1. Collections were made in as many habitats as possible. The habitats included in each collection stations are given in the following summation. Station 1. Bedstead Spring, 2.5 miles east of Boulder on Valmont Road, elevation 5300'. Habitats: Lush meadow, dry meadow, cottonwood bottom, buildings. Station 2. Boulder Canyon, state highway 119j elevation 6500'. Habitats: Lush meadow, dry meadow, north facing slope, south facing slope, east facing slope, west facing slope. Station 3. Boulder Canyon, state highway 119J elevation 7500'. Habitats: Lush meadow, dry meadow, north facing slope, south facing slope, east facing slope, west facing slope. Station U. Bluebird Ranch, northwest of Nederland, Colorado; elevation 8500*. Habitats: Lush meadow, dry meadow, aspen groves, coniferous forest. Station 5. Science Lodge, northwest of Nederland, Colorado} elevation 9500'. Habitats: Lush meadow, dry meadow, aspen groves, coniferous forest. Station 6. Northwest of Science Lodge toward Niwot Ridge} elevation 10,500'. Habitats: Lush meadow, dry meadow, aspen groves, coniferous forest. Station 7. Niwot Ridge, elevation 11,700'. Habitats: Tundra

and wind timber. Station 8. Arapahoe Peak} elevation 13,506' and the boulder fields on Longs Peak} elevation Hi,000'. Habitats: Gravelly rock and boulders on Arapahoe Peak and boulders on Longs Peak* Additional spot collections were made north of Boulder at four-mile mesa, Lyons, Colorado and along Highway 87 between 8 9

Boulder Junction and Longmont. A word of explanation is needed for the terms "lush" and "dry" meadows. The distinction between the two was made simply on the basis of density and vigor of the grasses on the area. The "dry" meadows (Figure 2) were characterized by a relatively low density. In addition, plant vigor was reduced apparently because of low available moisture and of soil conditions. The "lush" meadows (Figure 3) were characterized by a relatively high density and high plant vigor which was reflected in the larger size of indiv­ idual plants and the general appearance of luxuriant growth. An attempt was made to choose meadows which were not subjected to grazing so that the araneid population would not be affected by grazing and movements of livestock. In some cases this was not

Figure 2. Dry meadow, Bluebird Ranch near Nederland, Colorado. Topical of dry meadows at all elevations. Figure 3. Lush meadow, Boulder Canyon, 7500'. Typical of lush meadows at all elevations* entirely possible, but grazing pressure was always at a very low level* The cottonwood (Populus fremontii) bottomland (Figure k) at which collections were made is located in the plains zone. North Boulder Creek flows through the area. Cottonwoods and willows are present in abundance and a dense stand of tall grasses and herbs make up the understory. This stratum provides a very favorable habitat both for species living on the ground and species which live on grasses and herbs. The north facing slopes (Figure 5) are characterized by a thick stand of ponderosa pine (Pinus ponderosa) and a small number of Douglas fir (Pseudotsuga taxifolia). Grasses are very sparse and the shrubs few in number except for an occasional patch of very Figure k* Cottonwood bottom, Yalmont Road, east of Boulder.

0

Figure 5. North facing slope, Boulder Canyon, 65001. 12

thick, shrubby growth. South facing slopes (Figure 6) are virtually the opposite of north facing slopes. Here is found an open stand of ponderosa pine with an understory of shrubs and grasses. South facing slopes are, of course, much drier and the temperature higher than on the opposite slopes.

J Figure 6. South facing slope, Boulder Canyon, 6500'.

There is little difference between east and west facing slopes. The density and composition of trees, shrubs and grasses are virtu­ ally the same except in cases where there is a difference in degree of slope exposure. In general the west facing slopes are somewhat drier than the east facing, but I do not believe this difference is great enough to cause variations in the population. 13

The aspen (Populus tremuloides) groves in which collections were made are open stands with an understory of a few shrubs and grasses* The understory distinguishes them from the coniferous forest in the montane and sub-alpine zones where there is no under­ story. The principal trees in the coniferous forest are Engelmann spruce (Picea engelmanni) and lodgepole pine (Pinus contorta) in the montane zone and Engelmann spruce, limber pine (Pinus flexilis) and sub-alpine fir (Abies lasiocarpa) in the sub-alpine zone. An understory of blueberry (Vaccinium) is usually present and the forest floor is covered with a thick carpet of duff and litter. The tundra (Figure 7) is characterized by a low, dwarfed, often matlike vegetation having a high proportion of grasses, sedges and herbs. Woody plants are present but are usually prostrate due to high winds. Mosses and lichens grow wherever there is a favor­ able habitat. The tundra habitat would be excellent for species which live on the ground, were it not for the rigorous climate, as the large number of rocks and the matlike vegetation offer very

good places for concealment and cover. Two mountain peaks were also included in the collecting stations, but only one trip was made to each of these peaks. The surnit of Arapahoe Peak is characterized by gravelly rock and large boulders while the boulder fields on Longs Peak (Figure 8) are what the name implies. No vegetation is present on either of

the summits* Standard collecting procedures were followed. In the meadows where many species are to be found on grasses and herbs a sweep lit

Figure 7. Tundra and wind timber, Niwot Ridge.

Figure 8. Boulder fields on Longs Peak. net was used* In areas where grasses and herbs were not present it was necessary to look for the webs of web-building species and to turn over rocks, logs and other material to find species which live on the ground. Two other techniques were valuable especially for small species. The first of these was to spread a cloth under a shrub or small tree and shake the spiders onto the cloth. A considerable number of specimens were collected in this manner* The other technique consisted of sifting duff and litter from the coniferous forest floor. Only a few specimens were collected by this method, however* All specimens were preserved in seventy per cent alcohol*

DISCUSSION

Hie total collection for the purpose of this thesis amounted to 1212 specimens. Included in the total are seventeen families, seventy-five genera and 102 species. A tabulation by families giving the number of specimens found in each life zone (Table I in appendix) shows immediately that the number of individuals decreases in each succeeding zone from plains to alpine. Ibis is to be expected due to the more rigorous climate found at higher altitudes, and it is also in agreement with observations made by other workers on various groups of animals. Table I also reveals that six families were found in all five life zones, two families were found in four zones, one family was found in three zones, two families were found in two zones and six families were found in only one life zone. The zonal distribution 16

by families as given in Table I should not be considered conclusive, however. There are some obvious omissions in the collection data. Of the six families that are found in only one life zone, only one specimen was collected for the Hahniidae, and Mimetidae, two for the Uloboridae, seven for the Pisauridae and nine for the Clubionidae. The species included in these six families are evident­ ly rare, however, and it is possible that further collections will substantiate their restriction to one zone. If specimens are collected at other elevations it is questionable that they will ever be found in more than two or possibly three life zones. The specimens of and Pholcidae were found in only two life zones. A total of fifty Agelenid specimens, thirty-five in the plains and fifteen in the foothills seems to indicate clearly that the family Agelenidae is restricted to the two zones listed. The situation in the Pholcidae, however, with a total of only five specimens, is not at all certain. It is entirely possible that their range will extend into the montane zone. Only the Amaurobiidae were represented in three life zones. Here again the total number of specimens was small and there is no justification for restricting the members of this family to only three life zones. Further collection is needed to substantiate or reject their present distribution. The Argiopidae and Dictynidae were found in four life zones. The Argiopidae should be found in all zones since Aculepeira aculeata Chamberlain and Ivey has been collected on Loveland Pass and Trail Ridge by Walker Van Riper and on Arapahoe Peak by 17

Dr. Gordon Alexander. This species has a very wide boreal distri­ bution, being found in Europe as well as North America. The environmental niche occupied by A. aculeata is very interesting. According to Van Ripers It is always found above timberline and appears to prefer exposed and windy situations generally in big rock falls. Often the web foundation lines extend from boulder to boulder a distance of eight or ten feet supporting the two foot web. The only zone in which the Dictynids were not represented -was the sub-alpine. It is not reasonable that members of this family should be found at both higher and lower elevations, and be absent in the sub-alpine zone. The peculiar distribution shown by the data for this family is undoubtedly due to a failure to collect Dictynid specimens in the sub-alpine zone, or it may be that the specimens found in the alpine zone were carried there by rising air currents. If that is the case the Dictynids would only be accidental residents in the sub-alpine and alpine zones* The Attidae, Gnaphosidae, Linyphiidae, Lycosidae, Theridiidae and Thomisidae are found in all five of the life zones in Colorado* Of these six families, only the Linyphiidae and Theridiidae are web-builders while the other four pursue their prey. It might at first glance be supposed that fewer web-building families in the alpine zone are due to high winds. As explained previously, however, the Argiopidae and Dictynidae are also found in the alpine zone and both of these families are web-builders. The distribution among web-builders and ground species is therefore the same. It is interesting to note, however, that the total number of specimens 18 in the alpine zone is greatest for the ground species. This is especially true of the Attidae and Gnaphosidae. The greater number of ground species is emphasized by the data of Glick (1939), who pointed out that the Linyphiidae and Lycosidae respectively are most often found ballooning. Owing to the small numbers collected, it is doubtful whether the Linyphiidae, Lycosidae, Theridiidae or Thomisidae are resident alpine species. Only five or less specimens were collected for each of these four families, and those are insufficient to warrant positive conclusions. Table II shows the altitudinal distribution of genera. Of the seventy-five genera collected, it will be seen that thirty-nine are stenozonal, occurring in only one zone. Nineteen of these occur in the plains, nine in the foothills, four in the montane, two in the sub-alpine and five in the alpine. As expected, the majority of the stenozonal genera occur in the plains. It is somewhat surprising, however, to find that more genera occur in the alpine zone than in either the montane or sub-alpine. Balloon­ ing seems to be a probable cause for such a distribution. The fluctuating diurnal-nocturnal winds which are found over large mountain masses, such as the Rockies, could easily carry spiderlings to a zone in which they would not normally be found. Eight genera occur in two zones. The distribution of Pirata and Sosticus is discontinuous, however, and cannot be considered conclusive. In addition, the total number of specimens for genera occurring in two zones is generally small and, therefore, not too reliable. Further collections are needed to substantiate this data. Of the thirteen genera occurring in three zones, Euophrys, Herpyllus and Zelotes show a discontinuous distribution. The one specimen of Zelotes collected in the alpine zone was most certainly of accidental occurrence since no specimens were collected in

either the montane or sub-alpine zone. The distribution of Tibellus seems peculiar at first sight because two, twenty-five and fifty-eight specimens were collected in the plains, foothills and montane zones respectively. It might reasonably be assumed that this genus should also be found in the sub-alpine zone since the greatest number of specimens was collected / in the montane. I believe, however, that Tibellus can be limited justifiably to the lower three zones. The natural habitat of the genus Tibellus is on the stems and leaves of grass, consequently, large numbers can be collected in a sweep net. If the genus occurred at higher elevations there is little doubt that it would have been

collected. Twelve genera were found in four zones with Dictyna, Haplo- drassus, Thanatus and Theridion exhibiting a discontinuous distrib­ ution. With the exception of Dictyna, it is difficult again to say whether they are natural residents at the higher altitudes or were carried there by rising air currents. The small number of specimens collected in sane instances prohibits absolute zonal restriction at this time. More collections must be made before definite assertions can be justified. As a rule the genera occurring in a greater number of zones are represented by a greater number of specimens. This may indicate 20 that euryzonal species are better able to adapt to all aspects of their environment and therefore are more successful competitors, or it may indicate that the niches they occupy are present over a greater range in elevation. A combination of the two factors is probably the more plausible explanation. A further breakdown on altitudinal distribution by species provides more interesting information. Table III gives the number of specimens of each species and the general altitudes at which they were collected. In addition, Table I H serves as a list of all specimens collected for the study. It will be noted that in many cases specimens are identified only to genus. The reason for this is that the major distinguish­ ing species characteristics of spiders are in the form of the epigynum for the female and the palpus for the male. Since the sexual organs are not evident on immature specimens it is often impossible to make a positive identification. One Attid, one Linyphiid and four Gnaphosids were determined only to family. These specimens were so immature that it was impossible to identify them further, and are included only to make the record more complete. There are many factors affecting the vertical distribution of any group of organisms and among the most important are the environ­ mental forces which play such a large part in developing this pattern of both plant and animal life. As altitude increases, temperature decreases, the sumner season becomes shorter, and the winds are usually stronger. The short summer season is one impor­ tant limiting factor for life at higher elevations. The organism 21

must be adapted so that its life cycle can be completed in a very short length of time, or it must extend its life cycle over two years or more. The majority of spiders at high altitudes reproduce on a two-year cycle. The egg sacs are prepared in August or early September, the eggs lie dormant over the long winter season and the young emerge as the weather warms in late May or June. After the young have emerged, they must mature and mate in a relatively short period of time so that the reproductive cycle can be main­ tained. In addition to the short summer season, the problem of low temperatures and high winds must be taken into consideration. Night temperatures at high altitudes are low even in the months of July and August and, though not destructive of life, at least demand a relatively low temperature tolerance of resident organisms. High winds are not a severe hindrance to species which live on the ground, but have a decided influence on web-builders. This is evidenced by the small number of web-builders that are collected at high altitudes. Of these only one species, Aculepeira aculeata, builds large webs in exposed situations in the alpine zone. Other alpine species either pursue their prey actively on the ground or build small webs in the most sheltered places. The distribution of spiders is also dependent on factors other than climate. Indirectly, their distribution is influenced ty the vegetative cover, and, since spiders are carnivorous animals, they are directly dependent on the insect fauna in an area. Their carnivorous habits are not specific, however. Any insect not too large for the spider to handle will serve as food. Insects also 22

are not in all eases restricted to the zone or zones in which they are normally residents. The grasshoppers Melanoplus mexicanus mexicanus and M. occidentalis are good examples. They had pre­ viously been considered alpine species, but according to Alexander (1951) they are only accidental residents in the alpine zone. A similar situation very probably exists for many species of spiders. The lack of food specificity among spiders in general would thus permit them to range over several zones and occupy various habitats. Spiders are by no means restricted in movement. The phenomenon of ballooning is practiced by the majority of species and the fluctuating diumal-noctumal air currents in the Rocky Mountains provide a ready means of transport for spiders over a considerable range in elevation. As mentioned previously, Glick made collections of ballooning spiders up to an elevation of 15,000*. A total of 73k specimens were recorded between 1000 and 15,000’. The altitude which spiders may reach in ballooning and the fact that showers of gossamer have been met by ships hundreds of miles at sea un­ questionably establishes the ability of spiders to be carried great distances. Ballooning is very probably the cause, in many cases, of discontinuous vertical distribution. Gnaphosa muscorum, for example, was found in the foothills, montane and alpine, but not in the sub-alpine. For rare species it is also possible that specimens simply were not collected in a particular zone though they were present in both a higher and lower zone. That may have been the case with Phidippus formosus, since single specimens 23

were collected in the foothills, sub-alpine and alpine zones but none was found in the montane. Granting the incompleteness of data based only on one year of collecting, it appears, nevertheless, that spiders do exhibit a vertical zonation* Reference to Table III shows that of the total 101 species, sixty-nine were stenozonal, occurring in only one zone, fifteen were found in two zones, eleven in three zones, six in four zones and none in five zones* Converted to a percentage basis, 68 per cent occurred in one zone, 15 per cent in two zones, n per cent in three zones, 6 per cent in four zones and none in five zones. The greatest break, a difference of 53 per cent, lies between the unizonal species and those occurring in two zones. This difference is significant and emphasizes the validity of establishing some zonal distribution for spiders. Distribution patterns established on the basis of this study are not final and should be accepted with caution. In many instances the number of specimens was too small to be regarded as conclusive. Whether or not the species for which only a few specimens were collected are rare, is debatable. It is difficult to assign a numerical value beyond which a species could be con­ sidered common and below which it could be considered rare. A number could be arbitrarily chosen, of course, but it would not have a great deal of significance. Consequently, no attempt will be made to define a species as being common or rare. On the basis of field experience, however, some species are almost always seen in a particular habitat and these could be considered common* Agelenopsis utahana in buildings in the plains zone, Pardosa stemalis in meadows of the plains and Pardosa yavapa in the meadows of the foothills and montane zones are examples of common and characteristic species in the zones given. By reviewing the literature it was possible to determine that some species are distinctly boreal in distribution while others prefer a definitely austral habitat. The following ten species known to have a boreal distribution in North America also occur in the higher elevations of the Colorado Rockies: Aranea patagiata, Ceratinops rugosa, Cochlembolus alpinus, Euophrys monadnock, Lathys alberta, Lithyphantes albomaculatus, Orodrassus coloradensis, Iheridion rugosum and Yukon majesticum. The species seemingly adapted to austral regions in this continent were also collected at the lowest elevations in Boulder County: Agelenopsis pennsylvanica, A. potteri, A. utahana, Cicurina robusta, Hololena hola, Tegenaria domestica, Lycosa avida, L. carolinensis, L. helluo, Pardosa sternalis and Dolomedes scriptus. No attempt has been made to determine whether the species occurring in zones between plains and alpine agree with their geographic distribution. In addition to the species listed in Table III, three female specimens were collected which have not been identified. They represent the genera Allotheridion^ Haplodrassus and Paraphidippus and are probably new species. If so, they will be described as

soon as possible. SUMMARY

Collections for this thesis were made in 1951 and 1952 for the purpose of determining whether an altitudinal distribution exists for the Araneida. Five zones (plains, foothills, montane, sub-alpine and alpine) were represented in the collection. A variety of habitats was included at each collection station. Collections were made at 1000* intervals. A total of 1212 specimens were obtained representing seven­ teen families, seventy-five genera and 101 determined species. The total number of specimens decreased with increasing elevation, A definite zonal distribution exists for spiders despite certain negative aspects of the study. Sixty-nine of the total 101 species were stenozonal. Factors complicating the study of vertical distribution among spiders are the physical environment, especially length of seasons and temperature, similar habitats in a number of zones, carnivorous diet, balloon­ ing and the small number of specimens collected for some species. A list of boreal species and another of species adapted to austral regions are given. Three female specimens representing the genera Allotheridion, Paraphidippus and Haplodrassus were collected but have not yet been identified. They are probably new species and will be described as soon as it becomes certain they have not been pre­ viously recorded. SELECTIVE BIBLIOGRAPHY

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Blake, I.H. 191*5. An ecological reconnaissance in the Medicine Bow Mountains. Ecol. Monog. 15:207-21*2. Blauvelt, H.H. 1936. The comparative morphology of the secondary sexual organs of Linyphia and some related genera, including a revision of the group. Festschrift E. Strand, Riga 2:81-172. Bonnet, Pierre. 191*5. Bibliographia Araneorum. Vol. 1, 832 p. Publ. by author: Toulouse. Bristowe, W.S. 1938. The classification of spiders. Proc. Zool. Soc. London, ser. B, 108 (part 2):285-322, Cary, Merritt. 1911* A biological survey of Colorado. U.S. Dept. Agric., No. Amer. Fauna 33:1-256. Chamberlin, R.V. 1901*. Notes on generic characters in the Lycosidae. Canad. Entom. 36:173-178. . 1908. Revision of North American spiders of the family Lycosidae. Proc. Philadelphia Acad. Nat. Sci. 110: 158-318. • 1919. New western spiders. Ann. Entom. Soc. Amer. 157239-260. . 1920. New spiders from Utah. Canad. Entom. 52:193-200. ______. 1922. The North American species of the family Gnaphosidae. Proc. Biol. Soc. Wash. 35:11*5-171. ______• 1936a. Records of North American Gnaphosidae with descriptions of new species. Amer. Mus. Nov. 81*1:1-30. ______. 1936b. Further records and descriptions of North American Gnaphosidae. Amer. Mus. Nov. 853:1-25. ______• 19l*7 • A summary of the known North American Amaurobiidae. Bull. Univ. Utah 38. Biol. Ser., 10:5-31. • 191*8. The genera of North American Dictynidae. Bull. Univ. Utah 38. Biol. Ser., 10:1-31. Chamberlin, R.V. and W.J. Gertsch. 1930. On fifteen new North American spiders. Proc. Biol. Soc. Wash. !*3:137-U*i* ______. 19l*0. Descriptions of new Gnaphosidae from the United States. Amer. Mus. Nov. 1068:1-19. Chamberlin, R.V. and W. Ivey. 1933. Spiders of the Raft River Mountains of Utah. Bull. Univ. Utah 23. Biol. Ser., 2:1-79. Chamberlin, R.V. and ¥. Ivey. 1935. Miscellaneous new American spiders. Bull. Univ. Utah 26. Biol. Ser., 2:1-79. ______. 1936. New spiders from Mexico and Panama. Bull. Univ. Utah 27. Biol. Ser., 3:1-103. • 19l*0. Agelenid spiders of the genus Cicurina. Bull. Univ. Utah 30. Biol. Ser., 5:1-108. . 19l|la. Spiders collected by L.W. Saylor and others, mostly in California. Bull. Univ. Utah 31. Biol. Ser., 6:l-i*9. ______* 19Ulb. North American Agelenidae of the genera Agelenopsis, Calilena, Ritalena and Tortolena. Ann. Entom. Soc. Amer. 3U:585-62$. . 19U2. A hundred new species of American spiders. guTTTUniv. Utah 32. Biol. Ser., 7:1-117. ______• 19U3. New genera and species of North American Linyphiid spiders. Bull. Univ. Utah 33. Biol. Ser., 7:1-39. . 19Uu Spiders of the Georgia Region of North America. Bull. Univ. Utah 35. Biol. Ser., 8:1-267. . 191*6. On several new American spiders. Bull, Univ. Utah 36. Biol. Ser., 9:1-15. . 19U7a. The spiders of Alaska. Bull. Univ. Utah 37. Biol. Ser., 10:1-103. , 19U7b. North American Dictynid spiders: the Bennetti group of Amaurobius. Ann. Entom. Soc. Amer. 1*0:29-55. Chickering, A.M. 1938. Anyphaenidae and Clubionidae of Michigan. Papers Mich. Acad. Sci., Arts and Letters 2U:U9-8U. ______. 1939. The Thomisidae (crab spiders) of Michigan. Papers Mich. Acad. Sci., Arts and Letters 25:189-237. . 19i*3. The Salticidae (Jumping spiders) of Michigan. Papers Mich. Acad. Sci., Arts and Letters 29:139-222. . 1951. New and rare spiders from Wisconsin and adjoin- ing states. Amer. Mus. Nov. I501:l-ljl. Chopard, L. 19U5. Orthopteroides recueillis dans les montagnes du Cameron par la mission Lepesme, Paulian, Villiers. Rev. Franc. Entom. 11:156-178. 29

Cloudsley-Thompson, J.L. 191*8. Observations on the ecology of in Northwest Iceland. Ann. and Mag. Nat. Hist., 12th ser. 1:1*37-1*1*7.

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----- . 1907. Some Coleoptera and Arachnida from Florissant, Colorado. Bull. Amer. Mus. Nat. Hist. 23:617-621. Comstock, J.H. 19l*0. The spider book. Rev. by W.J. Gertsch. 729 p. New York: Doubleday, Doran & Co., Inc. Crosby, C.R. 1929. Studies in North American spiders: the genus Cochlembolus. Entom. News 1*0:79-82, D*Amour, F.E., F.E. Becker and W. Van Riper. 1936. The black widow spider. Quart. Rev. Biol. 11:123-160. Denis, Jacques. 19l*3a. Notes sur la faune des Hautes Fagnes en Belgique. IX. Araneidae. Bull. Mus. Roy. Hist. Nat. Belgique 19:1-28. N ______• !9^3b. Chasses arachnologiques dans les Pyrenees- onentales (Region de Banyuls-sur-Mer et Vallespir). Bull. Soc. Hist. Nat. Toulouse 78:117-127.

* 19S>0. Spiders from East and Central African mountains collected by Dr. G. Salt. Proc. Zool. Soc. London 120:1*97-502. Dodds, G.S. 1919. Altitudinal distribution of Entomostraca in Colorado. Proc. U.S. Nat. Mus. 51*:59-87. * 1920. Entomostraca and life zones. A study of distribution in the Colorado Rockies. Biol. Bull. 39:89-107. Dodds, G.S. and F.L. Hisaw. 1925. Ecological studies on aquatic insects. IV. Altitudinal range and zonation of mayflies, stoneflies and caddis flies in the Colorado Rockies. Ecol. 6:380-390.

Emerton, J.H. 1890. New England spiders of the families Drassidae, Agelenidae and Dysderidae. Trans. Conn. Acad. Sci. 8:166-206. Emerton, J.H. 18 9l*. Canadian spiders. Trans, Conn. Acad. Sci. 9:1*00-1*29. ______. 1911. New spiders from New England. Trans. Conn. Acad. Sci. 16:383-1*07. . 1913. New and rare spiders from within fifty miles o? New York City. Bull. Amer. Mus. Nat. Hist. 32:255-260. ______• 1919. New spiders from Canada and the adjoining states. No. 2. Canad. Entom. 51:105-108. ______. 1926. New spiders from Canada and the adjoining states. No. 5. Canad. Entom. 58:115-119. Exline, Harriet. 1938. The Araneida of Washington: Agelenidae and Hahniidae. Univ. Wash. Publ. in Biol. 9:1-1*1*. Folsom, J.W. and R.A. Wardle. 1931*. Entomology with special reference to its ecological aspects. i*th rev. ed., 605 p. Philadelphia: P. Blakiston's Sons and Co, Gertsch, W.J. 1932. A new generic name for Coriarachne versicolor Keyserling, with new species. Amer. Mus .Nov. 563:1-71 ______. 1933a. Notes on American spiders of the family Thomisidae. Amer. Mus. Nov. 593:1-22. ______, 1933b. New genera and species of North American spiders. Amer. Mus. Nov. 636:1-28. . 1933c. Diagnosis of new American spiders. Amer. Mus. Nov. 637:1-11*. . 193l*a. Notes on American crab spiders (Thomisidae). Amer. Mus. Nov. 707:1-25. ______, 193l*b. Further notes on American spiders. Amer. Mus. Nov. 726:1-26. ______, 1935. New American spiders with notes on other species. Amer. Mus. Nov. 805:1-21*. . 1939. A revision of the typical crab-spiders (Mxsumeninae) of America north of Mexico. Bull. Amer. Mus. Nat. Hist. 76:277-1*1*2.

_____ . 19l*la. New American spiders of the family Clubionidae I. Amer. Mus. Nov. 111*7:1-20. ______. 19i»lb. New American spiders of the family Clubionidae II. Amer. Mus. Nov. 111*8:1-18. 31

Gertsch, W.J. 191*2. New American spiders of the family Clubionidae III. Amer. Mus. Nov. 1195:1-18. ______. 19l*6a. Five new spiders of the genus Neoantistea. Jour. New York Entom. Soc. 51*:31-37* ______. 19l*6b. Notes on American spiders of the family Dictynidae. Amer. Mus. Nov. 1319:1-21. ______. 19l*9. American spiders. 285 P* New York: D. Van Nostrand Co., Inc. • 1951. New American Linyphiid spiders. Amer. Mus. Nov. I5li*:l-ll. Gertsch, W.J. and A.F. Archer. 19l*2. Descriptions of new American Theridiidae. Amer. Mus. Nov. 1171:1-16. Gertsch, W.J. and L.I. Davis. 19l*0. Report on a collection of spiders from Mexico. II* Amer. Mus. Nov. 1059:1-18. ______. 191*2. Report on a collection of spiders from Mexico* IV* Amer. Kus. Nov. 1158:1-19* ______* 191*6. Report on a collection of spiders from Mexico. V. Amer. Mus. Nov* 1313:1-11* Gertsch, W.J. and W. Ivey. 1936. Descriptions of new American spiders. Amer. Mus. Nov* 858:1-25* Gertsch, W.J. and W.L. Jellison. 1939* Notes on a collection of spiders from Montana. Amer. Mus. Nov, 1032:1-1*99* Gertsch, W.J. and S. Mulaik. 19l*0. The spiders of Texas. I* Bull. Amer. Mus. Nat. Hist. 77:307-31*0* Gertsch, W.J. and H.K. Wallace. 1935* Further notes on American Lycosidae. Amer. Mus. Nov. 79l*:l-22. Glick, P.A. 1939* The distribution of insects, spiders and mites in air. U.S. Dept. Agric. Tech. Eull. No. 673:1-150* Gregg, R.E. 19l*7* Altitudinal indicators among the Formicidae. Univ. Colorado Studies, Ser. D, 2:385-1*03* Haubold, Verna Lee. 1951* Distribution of the Carabidae (Coleoptera) of Boulder County, Colorado. Amer. Midi. Nat. 1*5 :683- 710. Hesse, R., W.C. Allee and K.P. Schmidt. 1937* Ecological animal geography. 597 p* New York: John Wiley & Sons. Hull, J.E. 1920* The spider family Linyphiidae. Vasculum 6:7-11. Jones, Sarah E. 19l*7. Descriptions of some species of the spider genus Dictyna. Field and Lab. 15s1-35. Kaston, B.J. 1938. Family names in the order Araneae. Amer. Midi. Nat. 19:638-61*6. ______. 19l*3. Supplementary notes on family names in the order Araneae. Amer. Midi. Nat. 30:765-768. • 191*8. The spiders of Connecticut. Conn. Geol. Nat. Hist.Surv., Bull. 70:1-871*. Kurata, T.B. 19l*9. Spiders (order, Aranea) from the district of Mackenzie. Canad. Entom. 81:127-131. Leng, C.W. 1912. The geographical distribution of Cicindelidae in eastern North America. Jour. New York Entom. Soc. 20:1-17. Levi, H.W. and L.R. Levi. 1951. Report on a collection of spiders and harvestmen from Wyoming and neighboring states. Zoologica 36:219-237. Lowrie, D.C. 191*2. The ecology of the spiders of the xeric dunelands in the Chicago area. Bull. Chicago Acad. Sci. 6:161-189. McCook, H.C. 1878. Note on the probable distribution of a spider by the trade winds. Proc. Acad. Nat. Sci. Philadelphia. 30:136-11*7. Merriam, C.H. 1892. The geographic distribution of life in North America with special reference to the Mammalia. Proc. Biol. Soc. Wash. 7:1-61*. . I89I*. The geographic distribution of animals and plants in North America. U.S. Dept. Agric. I89l*:203-211*. Washington: Gov‘t. Printing Office. Montgomery, T.H. Jr. 1901*. Descriptions of North American Araneae of the families Lycosidae and Pisauridae. Proc. Philadelphia Acad. Nat. Sci. 56:261-323. M^rgaard, E. 1952. The habitats of the Danish species of Pirata. Entom. Meddel. 26:1*15-1*23* Peckham, G.W. and E.G. Peckham. 1909. Revision of the Attidae of North America. Trans. Wisconsin Acad. Sci. 16:355-61*6. 33

Pennak, R.W. 19bl* An introduction to the limnology of northern Colorado. Univ. Colorado Studies, Ser. D, 1:203-220. Petrunkevitch, A. 1911. A synonymic index-catalogue of spiders of North, Central and South America -with all adjacent islands, Greenland, Bermuda, West Indies, Terra Del Fuego, Galapagos, etc. Bull. Amer. Mus. Nat. Hist. 29:1-809. • 1923. On families of spiders. Ann. New York Acad. Sci. 29 :lli$-l80. ______• 1926, The value of instinct as a taxonomic character in spiders. Biol. Bull. 100:1*27-1*32. • 1928. Systema Aranearum. Trans. Conn. Acad. Sci. ---- 2? 7i r ? 70. Ramaley, F. 1907. Plant zones in the Rocky Mountains of Colorado. Sci. n.s., 26:61*2—61*3. Rodeck, H.G. 1929. Zoology of a foothills area near Boulder, Colorado. Thesis: 1*5 p. Savory, T.H. 1928. The biology of spiders. 376 p. New York: The Macmillan Company. Tanner, V.M. and C.L. Hayward. 1931*. A biological study of the La Sal Mountains, Utah. Proc. Utah Acad. Sci. Rept. No. 1 (Ecol.) 11:209-235. Thorell, T. 1877. Descriptions of the Araneae collected in Colo­ rado in 1875 by A.S. Packard, Jr., M.D. Bull. U.S. Geol. & Geog. Surv. 3:1*77-528.

Van Riper, W. 1951* Guide to some common Colorado spiders. Univ. Colorado Mus. leaflet 8:1-21*.

Wallace, A.R. 1876. Geographical distribution of animals. Vol. 1, 503 p., Vol. 2, 607 p. New York: Harper Bros. Wallace, H.K. 1937* The use of the headlight in collecting nocturnal spiders. Entom. News 1*8:107-111. Zorsch, Helen M. 1937. The spider genus Lepthyphantes in the United States. Amer. Midi. Nat. 18:856-898. APPENDIX 35

TABLE I ALTITUDINAL DISTRIBUTION OF FAMILIES

Number of specimens Family name PF M S A Total

1. Agelenidae 35 15 50 2. Amaurobiidae 7 6 5 18 3. Anyphaenidae 1 1

k. Argiopidae 35 12 28 2 77 5. Attidae 39 23 15 11 18 106 6. Clubionidae 9 9 7. Dictynidae 75 12 23 13 123 « 8* Gnaphosidae lh 13 30 15 16 98 9. Hahniidae 1 1 10. Linyphiidae 11 26 1 5 3 U9 11. Lycosidae 106 81* 7h 33 5 302 12. Mimetidae 1 1

13. Pholcidae 1 h 5 lit. Pisauridae 7 7 15. Theridiidae 37 25 10 5 2 79 16. Thomisidae 80 101* 107 1* 2 297 17. Uloboridae 2 2

Totals hia 328 303 81 59 1212 36

TABLE II ALTITfTDINAL DISTRIBUTION OF GENERA

Number of specimens Genus name P F M S A Total

Genera occurring in one zone

l a Agelenopsis 31 31 2. 1 1 3* Arctosa 2 2 U* Asagena 2 2 5« Ceratinops 1 1 6. Cicurina 12 12

7» Clubiona 9 9 8« Cochlembolus 1 1 9# Goriarachne 3 3 10a Cyclosa 7 7 11* Dendryphantes 1 1 12. Dolomedes 6 6 13* Ebo 2 2

ilia Euryopis 5 5 15• Frontinella 15 15

1 6 a Geodrassus l 1 17a Granunonota 1 1 18a Hyptiotes 2 2 19a Icius 1 1 TABLE II (continued) ALTITUDINAL DISTRIBUTION OF GENERA

Number of specimens Genus name __.. > . P F M S A Total

Genera occurring in one zone

20. Lathys 12 12 21. Linyphia 9 9 22. Liodrassus 1 1 23. Mallos 1 1 2i). Marxia 1 1 25. Meioneta 1 1 26, Mimetus 1 1 , 27. Neoantistea 1 1 28. Philodromus 53 53 29. Pisaurina 1 1

30. Pityohyphantes h k 31. Pusillia 3 3 32. Salticus 9 9 33. Schizocosa 1 1 3l+. Tegenaria 1 1

35* Teutana 9 9 36. Tricholathys 2 2 37. Trochosa 2 2 38. Yukon 1 1 38

TABLE II (continued) ALTITUDINAL DISTRIBUTION OF GENERA

Number of specimens Genus name PF M s A Total

Genera occurring in one zone 39. Zygiella 1 1 Genera occurring in two zones

1, Evarcha 5 2 7 2* Hololena 3 3 6 3. Misumena 9 7 16 1*. Pellenes 1 1 2 So Pirata 1 1 2

6. Psilochorus 1 1* 5 7. Sosticus 1 1 2

8. Tarentula 2 2 1* Genera occurring in three zones

1* Araniella ’ 1 1 2 1* 2. Callobius 1 3 1 5 3. Euophrys 1 2 5 8 h. Herpyllus 3 1 1 5 5. Lithyphantes u 2 k 10 6. Lycosa 5 2 21 7. Nodocion 2 U l 7 8. Orodrassus 17 i 1 19 39

TABLE II (continued) ALTITUDINAL DISTRIBUTION OF GENERA.

Number of specimens Genus name P F M s A Total

Genera occurring in three zom5S

9. Steatoda 10 3 2 15 10. Tetragnatha 21 3 8 32

H o Tibellus 2 25 58 85 12. Titanoeca 6 3 1* 13 13. Zelotes 1 2 1 it Genera occurring in four zone:!

lo Aranea 12 1 17 2 32 2, Dictyna 75 10 22 1 108 3. Gnaphosa 5 3 7 3 18 1*. Habronattus 10 1 It 1 16 5. Haplodrassus 2 1 1 2 6 6. Latrodectus 16 10 3 1 30

7. Lepthyphantes 6 1 1 1 9 8. Metaphidippus 6 1 2 1 10

9. Misumenops • 15 Wt 9 1 69 10. Thanatus 1 10 1 1 13 * 11. Theridion 2 l 3 2 8 12. Xysticus 5 16 33 2 56 TABLE II (continued) ALTITUDINAL DISTRIBUTION OF GENERA

Number of specimens Genus name P FM SA Total

Genera occurring in five zones i

1* Drassodes 2 3 3 k 8 20 2. Pardosa 8U 77 71 33 5 270 2 i 3. 1 22 5 7 5 12 51

Totals ilia 328 303 81 59 1212 hi

TABLE III ALTITUDINAL DISTRIBUTION OF SPEGIES

Number of specimens Species name P F M S A Total

Family Agelenidae

Agelenopsis spp. k k Agelenopsis pennsylvanica (C.L. Koch) 3 3 A. potteri (Blackwall) 5 5 A. utahana (Chamb. and Ivey) 19 19 Cicurina robusta Simon 12 12

Hololena spp* 3 2 5 H. hola Chamb. and Gertsch 1 1 Tegenaria domestica Clerck 1 1

Family Amaurobiidae

Callobius spp. 1 1 2

C. nomeus Chamb. 3 3 Titanoeca spp. 3 3 h 10 T. silvicola Chamb. and tvey 3 3

Family Anyphaenidae

Anyphaena pacifica Banks 1 1 U2

TA.BLE III (continued) ALTITUDINAL DISTRIBUTION OF SPECIES

Number of specimens Species name P F M S A Total

Family Argiopidae

Aranea cavatica (Keys*) 1 1 2 A. gemnoides Charab* and Ivey k 1 5 A. patagiata Clerck 8 16 1 25 Araniella displicata lentz 1 1 2 h Cyclosa conica (Pallas) 7 7 Marxia stellata Walck. 1 1 Tetragnatha spp. 16 5 21 T. laboriosa Hentz 1 1 T. versicolor Walck. k 3 3 10 Zygiella montana Koch 1 1

Family Attidae

Attidae sp. 1 1 Dendiyphantes sp* 1 1 Euophrys monadnock Em. 1 2 8

Evarcha hoyi (Peckhara) 5 2 7 Habronattus spp* 10 1 k 1 16 Icius sp* 1 1 Metaphidippus spp* 2 2 it3

TA.BLE III (continued) ALTITUDINAL DISTRIBUTION OP SPECIES

Nunber of specimens Species name PF MSA Total

Family Attidae Metaphidippus aeneolus Curtis 2 1 3 K. nigromaculatus Keys* 2 2 1 5 Pellenes spp. 1 1 2

Phidippus spp* 1 2 1 It P. apachpanus Chamb* and - f e s f e — 1 1 P. audax (Hentz) 21 1 1 6 29 P. formosus Peckham 1 1 1 3 P. purpuratus Keys* 2 1 2 it 9

P, tyrrelli Peckham k 1 5 Salticus scenicus Peckham 9 9

Family Clubionidae Clubiona norvegica Strand 1 1 C* trivialis Koch 8 8

Family Dictynidae

Dictyna spp* Sk 9 21 1 85 D* longispina Em* 1 ‘ 1 D* sublata (Hentz) 1 1 Uh

TABLE III (continued) ALTITUDINAL DISTRIBUTION OF SPECIES

Number of specimens Species name P F M s A Total

Family Dictynidae Dictyna spp. volucripes group 21 21

Lathys spp* k h L* alberta Gertsch 8 8 Malios trivittatus Banks 1 1 Tricholathys spiralis Chamb* and Ivey 2 2

Family Gnaphosidae

Orassodes spp* 2 1 2 1 7 13 D, neglectus (Keys*) 2 1 3 1 7 Geodrassus spp* 2 2 Gnaphosa spp* 3 1 7 1 12 G* muscorom (L* Koch) 2 2 3 7 Gnaphosidae spp* 2 1 1 It Haplodrassus spp* 2 1 1 2 6

Herpyllus spp* 1 1 1 3 H* vasifer (Walck.) 2 2 Liodrassus sp* 1 1

Nodocion spp* 2 U 1 7 Orodrassus spp. lit 1 15 TABLE III (continued) ALTITUDINA1 DISTRIBUTION OF SPECIES

Number of specimens » Species name P F M S A Total

Family Gnaphosidae

Orodrassus coloradensis 3 1 J, CharaE.

Sosticus spp. 1 1 2

Zelotes spp* 1 2 l 5

Family Hahniidae

Neoantistea sp« 1 1

Family Linyphiidae

Ceratinops rugosa (Em.) 1 1 Cochlembolus alpinus Banks 1 1 Frontinella communis T^ientz) 15 Grammonota gentilis Banks 1 1 Lepthyphantes spp. 1 1 2 L. leprosa (Ohlert) 6 6 L. pollicaris Zorsch 1 1

Linyphia marginata 97 o “(FaTckT)---- "

Linyphiidae sp. 1 1 Keioneta sp. 1 1 TABLE III (continued) ALTITUDINAL DISTRIBUTION OF SPECIES

Number of specimens Species name P F M S A Total

Family Linyphiidae Pityohyphantes cristatus Chamb. and Ivey h k Pusillia mandibulata Em. 3 3 Yukon majesticum Chamb* and Ivey 1 1 Family Lycosidae

Arctosa parva Banks 2 2 Lycosa spp* 3 1 k L. avida Walck* 1 1

L* carolinensis Walck* 3 3 L. frondicola Em* 1 1 1 3 L* gosiuta Chamb* 1 1

L* helluo Walck* 9 9 Pardosa spp* h6 10 lOt 19 h 123 P* atromedia Banks 5 5 P* coloradensis Banks 3 1 1 5 P. conciima Thorell 1 6 7 P* distincta (Blackwall) 8 1 9 P* fuscula Thorell 1 1

P* mackenziana (Keys.) 2 6 7 1? kl

TABLE III (continued) ALTITUDINAL DISTRIBUTION OF SPECIES

Number of specimens Species name P F M S A Total

Family Lycosidae

Pardosa moesta Banks 1 1

P. sternalis Thorell 36 l 37 P. tristis Thorell 1 P. utahensis Chamb. 2 2 P. yavapa Chamb* k6 17 63 P. xerampelina (Keys*) 1 1 Pirata sp. 1 1 P. piraticus Clerck 1 Schizocosa avida Walck. 1 Tarentula spp. 2 T. kochi Keys, 2 Trochosa orophila Chamb, ani Gertsch 1 1 T« pratensis Em. 1 1

Family Mimetidae Mimetus hesperus Chamb.

Family Pholcidae Psilochorus imitatus Gertsch and Mulaik b8

TABLE III (continued) ALTITUDINAL DISTRIBUTION OF SPECIES

Number of specimens Species name P F M s A Total

Family Pisauridae

Dolomedes scriptus Hentz 6 6 Pisaurina sp* 1 1

Family Theridiidae

Asagena americana Em. 2 2

Euryopis scriptipes. Banks 5 5 Latrodectus mactans (Fabr.) 16 10 3 l 30 Lithyphantes albomaculatus (DeSeer) k k L. corollatus L. 2 h 6 Steatoda spp* 7 1 8 S* hespera Chamb* and Ivey 3 2 2 7 Teutana spp* k h T* triangulosa (Walck.) 5 5 Theridion spp* 1 1 1 3 T* differeus Em. 3 3 T. rugosum Em. 1 1 T. tepidariorum (C. Koch) 1 1 TABLE III (continued) ALTITUDINAL DISTRIBUTION OP SPECIES

n Number of specimens Clnar*-1 aq Ueulle P F M s A Total

Family Thomisidae Coriarachne utahensis Gertsch 2 2 C. versicolor Keys. 1 1 Ebo spp. 2 2 Misumena calycina (L.) 9 7 16 Misumenops spp. 7 1*2 5 1 55 M. asperatus (Hentz) 2 2 h M. celer (Hentz) 6 1* 10 Philodroraus spp. 32 32 P. alascensis Keys. 6 6

P. aureolus Clerck 3 3 P. spp. pernix group 11 11 P. rufus Walck. 2 2 Thanatus coloradensis Keys. 1 10 1 1 13 Tibellus spp. 2 25 58 85 T. raaritimus Menge 1* 1* Xysticus spp. 3 11* 29 1*6 X. benefactor Keys. 1 1

X. cuncator Thorell 1 1 1 1 h TABLE III (continued) ALTITUDINAL DISTRIBUTION OF SPECIES

* Nunber of specimens Species name P F M S A Total

Family Thoraisidae

Xysticus discursans Keys. 1 1 X. durus Sorensen 1 1 X. ferox (Hentz) 1 1 X. locuples Keys. 1 1 X. pellax Cambridge 1 1

Family Uloboridae

Hyptiotes spp. 2 2

Totals Wl 328 303 81 59 1212