[2Il] HYMENOPTERA 2 17 



2. Hind coxae not black , 4. 



Hind coxae always black, the middle usually black only at base. 

 Face below the insertion of the antennas yellow but -without a. 



median black line 3. 



Face below the insertion of the antennae yellow but 'with a me- 

 dian black line that extends to base of clypeus. 



Female : abdomen black but with the three or four apical segments, and 



segments 2 and 3 at apex, mostly rufous C. clypeattis. 



Male : abdomen mostly black, with usually the apical margins of seg- 

 ments 2 and 3 and 6 and 7, rufous ; there is also usually a median 



rufous spot on 3 and 4 C. clypeatus. 



3. Front and middle coxae at apex, -their trochanters and the hind tro- 

 chanters yellowish-white ; rest of coxae, and the hind femora black, 

 the hind tibiae and tarsi subfuscous, the front and middle legs ful- 

 vous ; abdomen black with the apex of the second segment, a broad 

 median stripe on the third at apex, and the sutures of the follow- 

 ing segments rufous C. nigrofemoralis. 



4. None in this section from Alaska. 



5. None in this section from Alaska. 



CTENISCUS CLYPEATUS Cresson. 



Cteniscus clypeatus CRESSON, Trans. Am. Ent. Soc., n, p. 113, 9, 1869. 



Mesoleptus concolor PROVANCHER, Nat. Can., vu, p. 139, 1875. PROVANCHER, 

 Fn. du. Can. Hym., p. 403, 1883. CRESSON, Syn. Hym. North America, 

 p. 212, 1887. DAVIS, Trans. Am. Ent. Soc., xxiv, p. 228, 1897. 



Type in collection of the American Entomological Society. From 

 St. Paul Island, August 15 to 25 (Fur Seal Commission). Many 

 specimens. Occurs in the White Mountains of N. H., the mountains 

 of Colorado, Hudson Bay Territory and in Oregon and Washington. 



CTENISCUS NIGROFEMORALIS sp. nov. 



Male. Length 7.8 mm. Black; face from some distance from 

 below the antennae, not immediately from their insertion, the clypeus, 

 except a black sutural line, cheeks, the mandibles except the teeth, and 

 scape and pedicel beneath, lemon-yellow; palpi, tegulae, a small spot 

 in front, epitegulae, apices of front and middle coxae, their trochanters, 

 and the hind trochanters yellowish- white ; rest of coxae and hind 

 femora black, the rest of the legs mostly reddish, the hind tibiae and 

 tarsi usually more or less obscured or subfuscous. Wings hyaline, the 

 stigma, except at apex and base, and the internal veins brownish. 

 Abdomen black with the apices of dorsal segments 2 and 3 and a 

 median stripe on the second, rufo-testaceous. 



Type. Cat. No. 5638, U. S. Nat. Museum. From Kukak Bay, 

 July 4. One specimen. 



