1979] 
Brady — Spider Genus Trochosa 
173 
genus Trochosa. At least two drawings of the female genitalia were 
made for each species: a ventral external view of the epigynum after 
all the hair had been removed (often revealing some internal struc¬ 
ture through the integument) and a dorsal view with the separated 
genitalia submerged in clove oil for clearing. The female genitalia of 
all species are drawn to the same scale. Two views of the male 
palpus were drawn for each species: a ventral view and a retrolateral 
view. The left palpus of the male was drawn after gentle removal of 
hair to reveal the palpal sclerites. All palpi are drawn to the same 
scale. The female genitalia and the male palpus are classically used 
in identifying spider species and they are of considerable importance 
in Trochosa for that purpose. 
Measurements. All measurements listed are in millimeters. Two 
net micrometers (0.5mm, 1.0mm) were used in an ocular (16X) with 
a combination of low (IX) and high (4X) power objectives for mak¬ 
ing measurements. The higher power combination was used in 
measuring the eye rows and was determined to be accurate to 0.2 
units of the micrometer grid or 0.025mm. The lower power combi¬ 
nation was used to measure the body dimensions and leg lengths 
and was determined to be acccurate to 0.2 units of the micrometer 
grid or 0.1mm. A measurement when retaken always read within 
two units of the original measurement with either of the micrometer 
grids, e.g., an original measurement of 6.5 micrometer units when 
retaken would read 6.3-6.7 units. In all cases the greatest dimension 
of the structure was recorded, e.g., patellea-tibia length was mea¬ 
sured as the greatest distance from a line tangent to the most prox¬ 
imal part of the patella to a line tangent to the most distal part of the 
tibia. 
The segments of leg I were measured from the prolateral aspect, 
as was patella-tibia II. The segments of leg IV were measured from 
the retrolateral aspect, as was patella-tibia III. This method was 
found to be accurate and resulted in fewer broken legs than others 
that were tried. Total body length was estimated by measuring the 
abdomen and adding this figure to carapace length. Although the 
anterior end of the abdomen tends to overlie part of the cephalo- 
thorax, the abdomen usually shrinks in alcohol, reducing its size. 
Measurements of total body length in this fashion can be repro¬ 
duced more accurately, and since this dimension is highly variable, 
its primary function is for general recognition, not definition of the 
species. 
