AMERICAN HYMENOPTERA. 387 



thorax, and tinged with yellowish on the vertex and mesothorax ; an- 

 terior orbits, dilated below, and a large triangular spot on each side of 

 the clypeus, white ; one specimen has the clypeus entirely white, while 

 another has it white with a black mark at base ; lateral margins of the 

 mesothorax and two small round spots on the scutellum, yellowish- 

 white; wings subhyaline, slightly stained with yellowish, the marginal 

 cell, the apical margin of both wings broadly fuliginous; legs black, 

 the coxae and femora clothed with white pubescence and the tibias and 

 tarsi with golden pubescence; tip of the anterior femora and their ti- 

 biae within and generally the intermediate tibiae within, fulvous ; ab- 

 domen shining, more finely punctured than the head and thorax, 

 clothed above with a short yellowish pubescence, long and white at 

 base; the first five segments each with an apical yellow fascia, broad 

 at the sides and attenuated toward the middle, interrupted on the mid- 

 dle of the first segment, and emarginate on each side of the first three 

 segments, the fascire on the fourth and fifth segments are the broadest ; 

 sixth segment with a large yellow mark, deeply notched anteriorly ; 

 venter with a very dense clothing of fulvous hairs, becoming whitish 

 toward the base. Length 5 — 6 lines. 



Male. — Same as the 9 j except that the face is clothed with a long 

 dense white pubescence, the anterior orbits, clypeus and mandibles, 

 except tips, are white; the mesothorax is margined laterally with whit- 

 ish in one specimen only, and the scutellum is immaculate in all the 

 specimens; the tibiae have a white spot at base and are tipped with 

 white, with a ferruginous spot at the extreme apex; tarsi white, dusky 

 at tips ; the fisciaj on the first four segments are slightly emarginate 

 on each side anteriorly, and that on the fifth segment is broad, slightly 

 constricted in the middle; the sixth segment is yellow, emarginate an- 

 teriorly with black, the apical edge is recurved and rounded ; apical 

 segment and venter black. Length same as 9 • 



Described from four 9 , four % specimens. Also taken in Colorado. 



34. AntMdium maculifrons, Smith. 



Antkidiuvi maculifrons, Smith, Brit. Mus. Cat. ii, p. 214. Cresson, Proc. Ent. 

 Soc. Phil, iii, p. 375. 

 One % specimen. 



35. Authidium atrifrons, n. sp. 



Female. — Black, densely and very finely punctured, clothed with a 

 dense whitish pubescence, that on the vertex and thorax above tinged 

 with fuscous; head entirely black, except a white spot at the summit 

 of each eye; anterior margin of the clypeus denticulated; four elong- 

 ate spots on the margin of the scutellum, the tubercles and the tegulae, 



