104 
Psyche 
[September 
(M in Fig. 3), radix (r), conductor (c) and a long embolus 
(e). The cymbium (y) is modified at its tip. 
Arctachaea differs from Theridion by having a hump on 
the abdomen (Figs. 6, 9, 10), and in the shape and direc- 
tion of the embolus. It differs from both Theridion and 
the closely allied Chrysso in having the tip of the male 
cymbium modified (Fig. 3). Arctachaea can be separated 
from Achaearanea which has a similar shaped abdomen in 
that the former has a radix in the male palpus while the 
latter genus does not. 
Arctachaea pelyx new species 
Plate 8, Figures 3-6, 12, 13 ; Map 1 
Types. Male holotype from East Canyon, Salt Lake Coun- 
ty, Utah, June 12, 1943 (W. Ivie) in the American Museum 
of Natural History. 
Description. Carapace yellow-white with a median dusky 
band, narrowest posterior, enclosing eye region and con- 
tinuing as a line across the clypeus ; sides of carapace with 
a dusky line. Sternum with a black border on each side. 
Legs with some black spots. Abdomen (Fig. 6) yellow- 
white with a dusky median dorsal band bordered by white. 
Anterior median eyes separated by one and one-quarter 
diameters, one-quarter from laterals. Posterior eyes sep- 
arated by one diameter. Abdomen with a tubercle (Fig. 6) 
that of male longer than high. Epigynum with a light 
swollen area illustrated by Figure 5, palpus by Figures 12, 
13. Total length of female 3.2 mm. Carapace 1.02 mm. 
long, 0.92 mm. wide. First femur, 1.71 mm.; patella and 
tibia, 1.85 mm., metatarsus, 1.58 mm. ; tarsus, 0.68 mm. 
Second patella and tibia, 1.11 mm.; third 0.78 mm.; fourth 
1.24 mm. Total length of male 2.7 mm. Carapace 1.15 mm. 
long, 1-10 mm., wide. First femur 2.71 mm.; patella and 
tibia 3.05 mm.; metatarsus 2.72 mm.; tarsus, 0.91 mm. 
Second patella and tibia, 1.63 mm.; third, 1.05 mm.; fourth, 
1.70 mm. 
Records. Utah : Salt Lake Co.: ESast Canyon, June 14, 
1942, 9 paratypes; June 21, 1942 9 paratypes; June 12, 
1943, 9 allotype, 9 $ paratypes (W. Ivie). Summit Co.: 
3 mi. W. of Wanship, June 20, 1941, 9 $ (W. Ivie) . Oregon . 
