476 
Psyche 
[September-December 
distinguish A. torridus from any one of the other Aliatypus species 
(Table 2) : PSL/PSS, CL/PSL, CL/IFL, and seminal receptacle 
form (Figs. 192- 194). 
Description. See Tables 1-3. 
Males: Carapace. Thoracic groove a deep pit with front wall 
broad and procurved ; transverse to slightly longer than wide ; nar- 
rowed posteriorly. Postocular setae grouped in form of narrow 
triangle. Sternum. Fig. 64. Posterior sigilla rather large and well 
separated. Pedipalp. Figs. 91, 1 19-120. Tibia swollen ventrally 
over most of its length. Embolus base distant from ICS base. Inner 
(concave) edge of OCS smooth to slightly rough. Leg I: Tibia and 
metatarsus setation very similar to that of A. plutonis. Abdomen. 
Tergites I and III reduced to small spots at bases of macrosetae. 
Coloration. Pars thoracica grey-yellow to pale brown. Pars cephalica 
darker; light brown to medium brown; darkest along margin and 
median longitudinal line. Chelicerae match either lighter or darker 
portion of pars cephalica. Pedipalps dorsally like pars thoracica. 
Females: Carapace. Thoracic groove a large, deep, roughly tri- 
angular pit with transverse anterior wall ; usually wider than long. 
Postocular setae form a long slender triangular grouping. Sternum. 
Fig. 77. Posterior sigilla large and well separated. Stout setae dis- 
tributed around entire periphery of sternum. Most of central setae 
extremely elongate. Genitalia. Figs. 192- 194. Seminal receptacles 
weakly to very weakly sclerotized. Stalks short, with 1 to 3 bends, 
thick, and same diameter throughout length. Bulbs rather large. 
Coloration. Pars thoracica pale yellow to pale brown. Pars cephalica 
darker; grey-yellow to medium brown; darkest along margins and 
median longitudinal line. Chelicerae medium brown. 
Variation. Males: Considering the large geographic distance sep- 
arating the two population samples, there is surprisingly little differ- 
ence in pedipalp and palpus form (Figs. 1 19-120). Moderately 
strong differences between these two small samples show up only in 
the following ratios: CL/ALS (El Paso Mountain sample with 
higher mean), CL/ITL (Mountain Center mean higher), and 
IFL/ITarL (El Paso Mountain mean higher). 
Females: Seminal receptacle form is remarkably similar throughout 
all three population samples (Figs. 192- 194). Noteworthy geographic 
variation occurs in five ratio characters. The Yucaipa sample 
(n = 2) has markedly smaller mean values of IMS/CTP and 
CL/CTP than both the Mountain Center (n = 4) and El Paso 
Mountain (n = 2) samples. In three other characters, CL/OQW, 
