110 U. S. NATIONAL MUSEUM BULLETIN 216 



dense, regularly spaced ; areolet usually narrower than in the podagricus 

 group, sometimes absent; hind spur of hind tibia rather slender, 

 together with its fringe of hairs about 4.0 to 5.0 as long as wide; last 

 segment of hind tarsus of female with or without a small, ventral, 

 subapical tooth or flange on inner side surmounted by a hair tuft; hairs 

 on abdominal tergites rather dense and regularly arranged, though the 

 basal three tergites with glabrous areas medially and the first tergite 

 often mostly glabrous (fig. 186, f); fourth tergite almost or quite com- 

 pletely covered with moderately dense, regularly arranged hairs; apical 

 notch of female subgenital plate usually weaker than hi the podagricus 

 group. 



1. Triclistus crassus, new species 



Figure 187,a 



Front wing 4.4 to 6.3 mm. long; face weakly mat, its punctures 

 rather coarse, separated by about 0.3 their diameter; temple of male 

 moderately convex, with dense hairs; metapleurum with 10 to 40 hairs 

 in male, with to 20 hairs in female; median longitudinal carinae of 

 propodeum moderately strong, sharp; areola rather regularly pentag- 

 onal but confluent with basal area, 0.5 as wide as basal area; costula 

 complete or almost complete, sharp and usually rather strong; outer 

 side of second lateral area of propodeum about 1.9 as long as inner 

 side; hairs on second lateral area dense; areolet present; hind spur of 

 hind tibia about 4.2 as long as wide; second segment of hind tarsus 

 about 2.2 as long as wide in male, about 2.1 as long as wide in female; 

 first tergite about 1.45 as long as wide in male, about 1.25 as long as 

 wide in female, its dorsal carinae extending about 0.53 its length; first 

 and second tergites a little more coriaceous than in other Nearctic 

 Triclistus, especially in the male; last segment of hind tarsus of female 

 with a very small subapical ventral tuft of hairs on inner side; apical 

 notch of female subgenital plate about 0.15 as deep as wide. 



Black. Antenna blackish brown, paler brown below, paling to 

 stramineous brown basally beneath; apical part of mandible fer- 

 ruginous; palpi pale brown; tegula fidvous or sometimes pale yellow 

 tinged with fulvous apically; legs fulvous. 



Type: 9, Muddy Pass, Colo., June 17, 1948, EL, M., D., and J. 

 Townes. (Washington, USNM 63627). 



Paratypes (171 cf, 409) : From Alaska (Anchorage, Berg Bay, Dutch 

 Harbor in Unalaska, King Salmon on the Naknek River, Mount 

 McKinley at 1,600 ft., Popoff Island, Sitka, Virgins Bay, and Yaku- 

 tat); Alberta (Banff, Cochrane, and Lethbridge); Arizona (near 

 Alpine); British Columbia (Bear Mt., Clinton, Likely, North Bend, 

 Robson, Vancouver, Vernon, Victoria, and Yoho Park); California 

 (Eureka, Glen Alpine Creek near Tahoe, San Anselmo, Siskiyou Co., 



