Psyche 
[September 
132 
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 (S. 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 abundant 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 F. 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 insulanus Bryant (1923), 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 
