1968] 
Coyle - — Spider Genus Atypoides 
189 
which difference is expressed by SL/SW for the females in Table II. 
The slight expansion of the posterior portion of the thoracic groove 
and the more posterior placement of the thoracic groove aid in iden- 
tification. Males. The palpus structure (Fig. 57) and the shapes 
and macrosetae distribution patterns of the tibia and the metatarsus 
of leg I (Figs. 71-73) are distinctive for this species. The small 
value of IML for A. hadros separates it from the other species 
(Table I). The shortness of both tibia and metatarsus of leg IV 
allows separation from the other species by IVTL/CL and IVML/ 
CL (Table I). The stiff non-attenuate setae forming the posterior 
half of the cheliceral apophysis and the form of the apophysis (Fig. 
46) helps to identify this species. Females. The wide seta-less area on 
the ectal side of the anterior half of the cheliceral macrotooth row 
is not found in the other species. The small number of IMS and 
CMT and the related ratio IVMCR/IMS (Table II) allow easy 
separation from the other species. PCT number (Table II) aids in 
di tingu’shing A. hadros from A. gertschi. Metatarsus I is relatively 
short (see IML/CL and IFL/IML, Table II) and also aids in 
identification. 
variation. Males. The two specimens from Feme Clyffe St. Pk. 
are much smaller than the average size of the 15 males from Pine 
Hills. The characters which show the most geographic variation 
are CAT/CL and PTL/CL. The cheliceral apophysis is thicker 
relative to body size in all Pine Hills males, and the palpal tibia is 
relatively longer in the Feme Clyffe St. Pk. males. Considerable 
intrapopulation variation exists in macrosetae number and placement 
on leg I ; the group on the retrolateral aspect of the ventral surface 
at the proximal end of the tibia contains from 2 to 7 macrosetae 
( 1 to 4 enciform macrosetae) and the prolateral group contains from 
4 to 15 macrosetae (4 to 14 enciform macrosetae). Figure 73 illus- 
trates a tibia with high numbers in each group of macrosetae. The 
left metatarsus I of 12 of the 15 males has 4 macrosetae positioned 
as in Figure Ji. In two specimens the distal prolateral macroseta 
is absent, and in one only this macroseta and the most proximal 
one are present. 
Females. The seminal receptacles of the three females are il- 
lustrated to show the variation in the prominence of the bowl. Fig- 
ure 89 has large bowls which are distinct from the stalks, Figure 88 
has slightly less prominent bowls, and Figure 87 has smaller bowls 
less clearly distinct from the stalks. 
distribution. Southern Illinois and eastern Missouri (Map 1). 
