A. R. Brady.
The Spider Genus Sosippus in North America, Mexico, and Central America (Araneae, Lycosidae).
Psyche 69:129-164, 1962.

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THE SPIDER GENUS SOSIPPUS IN NORTH AMERICA, MEXICO, AND CENTRAL AMERICA
(ARANEAE, LYC0SIDAE)l
BY A. R. BRADY
Harvard University
Introduction, The genus Sosippus contains the only spiders in the Nearctic Region of the subfamily Hippasinae, members of which are unique among the Lycosidae in producing a large funnel-web resem- bling that of the Agelenidae. The posterior spinnerets are more elong- ate than in other Lycosidae, concomitant with their web building habits. Although similar to the Agelenidae in these respects, they represent typical Lycosidae in other characters. In Sosippus the eyes are arranged in three rows: four small eyes on a vertical front form the anterior row; two large posterior median eyes form the second row, and two somewhat smaller posterior lateral eyes form a third row. The trochanters are notched and the egg case is carried attached to the spinnerets. These features are characteristic of all Lycosidae. but are not found in the Agelenidae. The tarsi and metatarsi of leg I and leg I1 are more densely scopulate in Sosippus than in most other lycosids. Sosippus is found in tropical and subtropical America from Costa Rica to the southern United States. Porrima, found in South America. appears to be the closest relative of Sosippus. Females of P. diwersa (0. P.-Cambridge) and the male holotype of P. harknessi Chamberlin resemble Sosippus in coloration and especially in external genitalia
(Figs. 12, 33)) but are readily
separated by differences in the eye arrangement (Fig. I I ). The Hip- pasinae of the Neotropical Region, in addition to eight described species of Porrima, are represented by two species of Birabenia and the mono- typic genus Hippasella. C. F. Roewer (1959) splits Porrima into three genera on the basis of the number of posterior cheliceral teeth and slight differences in the eye arrangement. On the basis of great varia- tion of these characters in Sosippus, it seems best to maintain the eight species in question in the single genus Porrima until further study. In the Ethiopian, Oriental, and Australian Regions the Hippasinae are represented by 12 genera containing numerous species according to C. F. Roewer ( 1959). These Lycosidae have in common one feature 'Published with the aid of a National Science Foundation Grant of the Department of Biology, Harvard University. Manuscript received by the editor March 19, 1962.



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130 Psyche
[September
that separates them from other lycosids, namely, the greater length of the posterior pair of spinnerets. If the greater length of the spinnerets is concomitant with web-spinning habits, then it would seem that this assemblage might constitute a natural group deserving subfamilial rank. If, however, the length of the spinnerets does not indicate a web-spinning function, but is simply a structural convergence found in otherwise diverse groups, it should not be used as a criterion to estab- lish a subfamily. It may be that some species of Eluprosthenops placed in the Pisauridae also belong to this group since the genitalia are simi- lar to those of Lycosidae and the eye arrangement resembles that of Porrima.
Acknowledgements. This investigation was carried out as a gradu- ate research program under the direction of Dr. H. W. Levi of the Museum of Comparative Zoology to whom I am especially indebted for encouragement, helpful advice, and constructive criticism. 3 thank sincerely Dr. W. J. Gertsch of the American Museum of Natural History, who placed the collections of his institution at my disposal. I thank also Dr. H. I<. Wallace of the University of Florida for making large collections from Florida available for study. Measure- ment of Wallace's specimens was not undertaken because the paper was near completion at the time of their arrival. Study of these speci- mens elucidates certain facts that I will stress, and supports the con- clusions already reached before their arrival. Locality data was uti- lized and certain structural features were checked. Mr. J. A. Beatty
provided a number of specimens from Arizona and Sonora and sup- plied ecological data for S. californicns. I am grateful to Dr. G. Owen Evans and to Mr. D. Clark of the British Museum, Natural History, for loan of the male of S. mexica~zz~s. Collections in the field during the summer of 1961 were made possible by a grant from the Sigma Xi-RESA Research Fund. A National Institutes of Health Grant (E-1944) helped defray some of the expenses. Sosippus Simon, 1888, Ann. Soc. Ent. France, 8 (6) : 206, Types species: The problem of the type species has been discussed by Bonnet ( 1958). I follow him for the sake of nomenclatural stabil- ity. Simon (1888) established the genus Sosippus and designated Dolomedes oblongus C. L. Koch as the type. At the same time he described Sosippus nzexicanus as a new species. In 1898 Simon trans-
ferred D. oblongus to the genus Lycosa (Diapontia) and established



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19621 Brady - Sosippus 131
S. mexicanus as the type species. Sosippus mexicanus has been assumed to be the type for the last 64 years.
Characteristics. Anterior eye row, as seen from in front, procurved. Lateral eyes subequal to the median eyes and mounted on distinct tubercles. Anterior eye row wider than the middle row; the posterior row wider than the anterior row (Fig. 10). Chelicerae robust, with prominent bosses. Anterior cheliceral margin with three teeth on each side. Posterior cheliceral margin with three or four cheliceral teeth on each side, rarely five. Usually constant within a species, but some- times variable, e. g. S. mirnus. Labium longer than wide, as long as wide, or slightly wider than long. Endites, heavily scopulate, slightly converging in front of labium, less heavily scopulate. Carapace with conspicuous longitudinal thoracic groove. Carapace of females highest in the cephalic region, of males usually highest in the thoracic region. Sternum always longer than wide. Fourth leg longest. Patella-tibia IV longer than metatarsus (except in males of S. californicz~s, which have the metatarsus longer). Order of length of patellae and tibiae: IV, I, 11, 111. Tarsi and metatarsi of legs I and I1 heavily scopulate. Tibia I and I1 usually scopulate at distal ends. Males with legs longes- than those of females and more heavily scopulate. Female epigynum characterized by a relatively narrow anterior median septum connected to an expansive posterior blade (Fig. 19). Male palpi with numerous sclerites (Fig. 36). The variable nature of certain morphological characters is empha- sized because some earlier authors considered such characters to be diagnostic for the genus. Some are diagnostic at the species level. Discussion. Spiders of the genus Sosipp,us represent a closely related group of species as evidenced by their structural similarity and web- spinning habits. It is probable that the group has diverged relatively recently in geologic time. Two species groups might be established on the basis of structural similarities and distribution. One group con- tains S. floridanus, S. 7ninzus, and 5. texanus. The other group includes 5'. californicus, S. 772 exicanus, S. ,agalenoides, S. michoacanus and 6'. flutonus. The illustrations of the color patterns and the drawings of the genitalia indicate the affinities within these two species groups. C. F. Roewer, first in the Katalog der Araneae (1954) without giving reasons, and then in 1959 attempted to separate Sosippus into two groups, giving each generic rank. This division is based entirely upon the number of teeth on the posterior cheliceral margin. Species with four cheliceral teeth on each side were left in Sosippus and those with three on each side were placed in the newly erected genus Sosip-



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Psyche [September
pinus. The division of the genus on this basis alone becomes untenable since the number of teeth on the posterior cheliceral margin is ex- tremely variable within certain species (8. mimus). Similarities in color pattern, eye arrangement, spination, relative length of leg seg- ments, and especially the genitalic characteristics indicate that the eight species considered in this paper should be maintained in a single genus. Simon described S. mexicanus (type of the genus) as having four posterior cheliceral teeth on each side. F. Pickard-Cambridge ( 1902) reported that the most abunda-nt species of Sosippus in Mexico, which he felt surely was the one described by Simon, had only three cheliceral teeth on each side. Of the two females of S. mexicanus examined, one has 4-3 posterior cheliceral teeth. It is very possible that the specimens of S. mexicanus that Simon had before him actually had four posterior cheliceral teeth on each side, which, in the case of mexicanus, turns out to be the exception rather than the rule. It is also very probable that I?. Pickard-Cambridge was describing the same species. Roewer's criterion of the number of posterior teeth of the chelicerae for defining genera is completely artificial in the case of Sosippus and probably other lycosid genera as well. J. Buchar (1959) has recently found that the lycosid genus Trochosa in Central Europe shows considerable variation within the same species in the number of posterior cheliceral teeth. The similarities among the eight species of Sosippus far out- weigh any differences that might be used to separate them into two or more genera.
Incorrect Placement. Sosippus insulams Bryant ( I 923)) described from Barbados, is an immature lycosid, evidently at the penultimate stage of development. The coloration, scopulae of the tarsi and meta- tarsi, and spinnerets are not like those found in Sosippus. Although the true identity of this specimen can be ascertained only after associa- tion with adult individuals from the same locality, it is best referred to the genus Lycosa at the present time. Measurements. Two sets of oculars with accompanying grids were used in combination with low and high power objectives for making measurements. From measuring a selected set of specimens several times, it was determined that the higher power combination was accur- ate to 0.02 mm and the lower power combination was accurate to 0.1 mm. In all cases the greatest dimension of the structure was measured, e.g. patella-tibia length was measured as the greatest distance between a line tangent to the most proximal part of the patella to a line tangent to the most distal part of the tibia. Measurements were made under conditions as uniform as possible. Conditions for the most important



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measurements are specified below. A series of 20 measurements involv- ing various components of the spider were made for each specimen. # >
1 he most diagnostic of these measurements are recorded for compai-i- son in Table I.
The posterior median eyes (PME) and the posterior lateral eyes (PLE), which form two rows in the Lycosidae, are referred to in this I I
Text Fig. 1. Measurement of the Posterior Ocular Quadrangle. paper as the posterior ocular quadrangle (POQ) . The measurement of the POQ is illustrated in Text Figure I. The distance A is the width of the anterior row of the POQ, the distance B is the length 01" the POQ, and the distance C is the width of the posterior row of the POQ. The length of the carapace was measured as the distance from the line tangent to the posterior-most part of the carapace to the line tangent to the anterior-most part of the AME. Total length was measured from the most anterior part of the AME to the tip of the anal tubercle, when this structure was visible, or to the posterior tip of the abdomen. When the specimen was stretched so that the lorum of the pedicle was visible (an abnormal attitude in the living spider), the abdomen was measured and the length of the carapace was added as the distance from the anterior



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Psyche
[September
TABLE 1
POSTERIOR OCULAR QUADRANGLE
Anterior Anterior Posterior
Species - N Eye Row
S. californicus 22 1.397 2 0.075
S. mexicanus 1 1.44
S. floridanus 3 1.29
1.1 7
1.24
S. mimus 4 1.47
1.50
1.49
1-50
S. texanus 2 1.75
1.79
S, agalenoides
s. plufonus
S. floridanus
S. mimus
S, texanus
Row
1.190k 0.051
1.17
1.12
1.05
1.10
1.22
1.25
1.22
1.27
1.45
1.42
Row
1.717 k 0.069
1.80
1.62
1.52
1.57
1.79
1.84
1.84
1.89
2.17
2.17
Length
1.031 k 0.049
All measurements are in mm with the mean and standard deviation calculated where 10 or more specimens were available.



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Brady - Sosippus
TABLE 1 (Continued)
Species
californicus
mexicanus
fioridanus
FEMALES:
califo~nicus
mexzcanus
CARAPACE
Length Width
6.9020.50 5-01 k 0.14
LABIUM
Length
1.037 2 0.065
0.99
0.89
0.84
0.84
1.07
1.12
1.15
1.14
1.40
1.40
Width
Total Body
Length
13.92 k 1.09
12.0
11.9
11.2
-
13.3
13.1
14.2
14.2
20.1
18.0




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Psyche
TABLE 1 (Continued)
SEGMENTS OF LEG IV
Species Femur
S, californicus 8.02k 1.96
S. mexkanus 7.6
S, floridanus 6.4
6.1
6.2
&', mimus 7.3
7.5
7.9
7.5
S. texanus 9.5
9.6
FEMALES :
8. californicus 7.65 2c 1.06
S. mexicanus 6.0
5.5
S. agalenoides 9.8
9.7
10.1
9.6
S. michoacanus 7.0
6.5
6.5
6.3
-
s. ~lutonus 5.7
8. fioridanus 5.72 * 0.63
8. mimus 7.0
7.0
6.0
7.4
8. texanus 7.43 2 1.62
Patella-
Tibia
9.43 & 2.31
8.8
7.4
7.1
7.5
8.4
9.0
9.4
9.2
11.6
11.8
8.86k 1.16
7.0
6.3
11.2
10.9
11.5
10.8
8.1
7.6
7.7
7.5
-
6.7
6.63 31 0.69
7.6
7.6
7.3
8.3
8.86 * 1.79
Metatarsus
9.95 31 2.36
8.6
6.7
6.7
7.0
8.0
8.5
9.2
8.7
11.0
11.0
8.26 * 1.06
6.5
5.9
9.6
9.4
9.7
9.4
7.5
6.9
7.0
6.9
-
5.8
5.83 * 0.59
6.9
6.9
6.2
7.0
7.30 * 1.24
Tarsus
[September
Total
All measurements are in mm with the mean and standard deviation calculated where 10 or more specimens were available.



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part of the indention in the posterior edge to the tangent of the AME, thus allowing for the abdomen over-hanging the carapace. Foi- meas- urements of the POQ the specimen was placed in a horizontal attitude such that a definite space was visible between the PME and the AhqE when viewed from above (as in Fig. 3 and not as in Fig. 4). This gives the gseatest length to the POQ. The antesior eye row was measured by placing the specimen vertically in such a position that a face view was obtained. The measurement of the AME was again checked in this positio~. The measurement of leg segments was taken from the psolateral aspect of the antesior pairs of legs and the retro- lateral aspect of the posterior pairs of legs for all segments except the femosa. The femora of the anterior pairs of legs wei-e measui-ed from the retrolateral aspect and those of the posterioi- pairs of legs fi-om the prolateral aspect to avoid bi-eaking legs from specimens, EXPLANATION OF FIGURES
The color descsiptions and illustrations of S. texan,us, 8. floridanus, and S. caZifornicus were based on fsesh specimens and represent these species nluch as they appear in life. The color description and illustra- tion of 8. 7nimus (Fig. 3) is based on the holotype, which is in very good condition. Sosifipz~s mich oacmus, S. qdenoides, S. nzexicanus, S. mi7?zus (Fig. 2), and 8. plutonus were drawn fsom specimens that have been in alcohol for some time, but have remained in a good state of preservation. The relative condition of these specimens is indicated by the order in which they are listed above. The description and illustration of the type of S. pZuion,z~s probably deviates more from that of the living spidei- than any of the rest since hair appeass to have been rubbed fsom the carapace and the abdomen is shrivelled. Two drawings of the female genitalia were made for each species: a ventral external view of the epigynum after a11 the hais had been removed (thus revealing some internal structui-e th-o~~gh the integu- ment), and a dorsal internal view with the genitalia removed and sub- merged in clove oil for clearing.
Two views of the male palpi were dl-awn for each species: a ventral view and a retrolateral view. The left palpi of the males were used after gently scraping them free of hair (quite abundant in the living spider) and spines (one 01- more at the ventral apex and several along the setrolateral edge of the cymbiun~). These hail-s and spines obsts~~ct the palpal sclei-ites and since the sclerites of the palpi are of much greater diagnostic value, no attempt was made to indicate hirsuteness or spination in the drawings of the male palpi.



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138 Psyche [September
SPECIES DESCRIPTIOATS
Before analyzing the individual species a few comments should be made concerning the treatment of certain sections. 8imciure. Under this heading follows a description of stl-uctural features not covered in the table of measurements and not defined specifically undei- generic characters. Tibia1 spination is relativel~l constant for each sex within a given species and there is a basic pattern throughout the genus. Therefore, two tables are constructed showi~~g the typical patterns of tibia1 spination in S. cdifonnicr~s and subseque~lt species are compared to these.
When the difference between two dimensions is less than 0.05 mm these dimensions are considered subequal. Color. Color descriptions are based on specimens submerged in alcohol and viewed at low power ( 10 X ) under a dissecting scope with illumination from a microscope lamp. In fresh alcoholic specimens the color is much the same as in the living spiders. The contrasting light and dark markings, particula~-ly on the carapace and dorsum of the abdomen, ase created