1974] 
Coyle — Genus Aliatypus 
457 
Diagnosis. The geographic range of this species (Map 3) is well 
separated from those of all other Aliatypus species. Males: Because 
of its proportionately long metatarsus I, short tarsus I, and short 
pedipalpal patella, A. isolatus is best distinguished from most of its 
congeners by the ratios IML/ITarL, PPL/PFL, and PTL/PPL 
(Table 1). The palpus structure (Figs. 107-109) of A. isolatus is 
distinctly different from that of most species. CL/ALS (Table 1 ) is 
the best character for distinguishing A. isolatus from closely related 
A. janus. Females: A. isolatus is extremely similar to A. janus and 
A. calif ornicus ; refer to diagnoses of these species. A. isolatus differs 
from similar A. aquilonius in having a transverse thoracic pit rather 
than a rounded or elongate one, and in its larger body size (especially 
longer tarsi; Table 2). A. isolatus can be separated from A. gwomus 
by seminal receptacle form (Figs. 144-146), AMD/AMS and 
CL/AMD (Table 2), and body size (Table 2). CL/IVTL, 
CL/IFL' and PSL/PSS (Table 2) clearly distinguish A. isolatus 
from all other species. 
Description. See Tables 1-3. 
Males: Carapace. Thoracic groove a deep transverse pit or groove. 
Postocular setae form a relatively long narrow row. Sternum. 
Fig. 56. Posterior sigilla small and far apart. Pedipalp. Figs. 80, 
107-109. Tibia swollen ventrally near distal end. Embolus base 
distant from ICS base. Conductor tapers rather evenly to narrow, 
sharp, angularly truncate tip which is bent. Inner (concave) edge 
of OCS smooth. Leg I. Tibia and metatarsus with all or nearly all 
ventral macrosetae attenuate; background setae elongate, slender, 
densely distributed, and not appressed. Abdomen. Tergite I small. 
Tergite III absent. Coloration. Pars cephalica and chelicerae light 
brown to dark brown ; much darker than light grey-yellow pars 
thoracica. Pedipalps darker than pars cephalica; medium orange- 
brown to dark red-brown. 
Females: Carapace. Thoracic groove a deep transverse pit or 
groove. Postocular setae row extends to point at least one-half of 
distance from anterior edge of carapace to thoracic groove. Sternum. 
Fig. 67. Posterior sigilla small and far apart. Peripheral setae 
slender. Longest setae scattered all over sternum. Genitalia. Figs. 
144-146. Seminal receptacles weakly sclerotized. Base of stalk rela- 
tively thick and nearly straight. Stalk becomes much narrower 
distally; long; 4-7 bends; often very irregularly looped. Bulbs small. 
Coloration. Pars thoracica pale yellow to pale yellow-brown. Pars 
cephalica darker; light yellow-brown to medium brown. Chelicerae 
slightly darker than pars cephalica. 
