24 



U. S. NATIONAL MUSEUM BULLETIN 216 



margin straight; mandible about 2.0 as long as wide, its upper tooth 

 somewhat larger than its lower tooth, its outer face smooth, with 

 some large weak punctures; flagellum with about 28 segments in male, 

 with about 23 segments in female; metapleurum with scattered hairs 

 in its upper 0.2; front spur of middle tibia about 0.73 as long as hind 

 spur; second segment of middle tarsus about 2.5 as long as wide in 

 male, about 2.25 as long as wide in female; second tergite with or 

 without a longitudinal carina just mesad of its spiracle, the tergal 

 sculpture composed of coarse, subadjacent punctures with a tendency 

 to longitudinal wrinkling between the punctures; apex of penis as in 

 Chorinaeus junebris, without setae. 



Colored like Chorinaeus excessorius except that hind coxa is blackish 

 with apex ferruginous. 



Specimens: 29, Big Delta, Alaska, June 24 and 30, 1951, W. R. M. 

 Mason (Ottawa), cf, Vancouver, B. C. (Washington), cf, 29, San 

 Francisco, Calif., Apr. 10, 1907, E. C. Van Dyke (San Francisco and 

 Townes). 9, San Francisco, Calif., May 10, 1908, E. C. Van Dyke 

 (Townes). d" (type), Santa Cruz Mts., Calif. (Washington). 9, Stin- 

 son Beach, Calif., Apr. 6, 1951, E. I. Schlinger (Townes). cf, Easton, 

 Wash. (Washington). 



The range is from Alaska to southern California. 



5. Chorinaeus opacitas Davis 



Figure 178,f 



Chorinaeus opacitas Davis, 1897, Trans. Amer. Ent. Soc, vol. 24, p. 210; 9 • 

 Type: ?, Nevada (Philadelphia) . 



Front wing 3.9 to 4.8 mm. long; face about 0.91 as high as mouth 

 is wide in male, about 0.85 as high in female; central 0.6 of clypeal 

 margin a little up-bowed; mandible about 1.85 as long as wide, its 



If N ' 



7 ^ — ■*— / 



Figures 8-10. — Localities: 8 (left), Chorinaeus californicus; 9 (center), C. opacitas; 10 



(right), C. constrictus. 



