1864.] 161 



middle of the face and the clypeus rufous, the latter with a yellow spot 

 on each side, the mandibles near their tips also rufous ; antennas two- 

 thirds the length of the body, black, the basal joint beneath yellow, 

 and the 8th to 12th joints yellowish-white, spotted beneath with black. 

 Thorax black, rather densely and closely punctured, shining, the tegular 

 and a spot before the wings honey -yellow ; a line beneath the wings 

 and the scutellum yellow, the latter flat, smooth and shining; meta- 

 thorax scabrous, the elevated lines well defined, the central area large, 

 quadrate. Wings subhyaliue, slightly stained with fuscous and having 

 a brassy gloss, the nervures and stigma testaceous, the areolet 5-angu- 

 lar. Legs black, apex of the anterior and intermediate femora and 

 the tibiai and tarsi yellow, the latter obfuscated at tips, the anterior 

 femora stained with ferruginous on the inside ; the posterior femora 

 entirely black, the basal half of their tibiae yellow, the tarsi dusky. 

 Abdomen black, the petiole rather slender ; first segment bilineated, 

 finely aciculate, the second and third segments above very finely and 

 closely punctured, the remaining segments smooth and shining • at the 

 base of the second and third segments above a rather narrow transverse 

 yellow band, the posterior margin of which is denticulated, that on the 

 second segment covering the base and extending down for a short dis- 

 tance on each side of the segment, that on the third segment not quite 

 reaching the base and is somewhat dilated on each side ; beneath, the 

 second, third and fourth segments are yellowish, the rest black ; ovi- 

 positor scarcely exserted. Length G lines; expanse of wings 11 lines. 

 ffiih. — Rocky Mountains, Colorado Territory. 



Section 7 — a. 



39. Ich. ambiguus. n. sp. 



Black : the face, orbits, two lines before the wings, scutellum and the ante- 

 rior legs in front, white; wings fuliginous; central area of metathorax small, 

 .subconical. 



Male. — Elongate. Head black, the face beneath the antennae, the 

 orbits interrupted behind, clypeus, spot on mandibles, and the palpi, 

 white ; antennas porrect, more than half the length of the body, black, 

 basal joint beneath white. Thorax black, shining, closely punctured ; 

 mesothorax in front with two impressed longitudinal lines reaching the 

 disk ; the collar above, an abbreviated sutural line before and a dot 

 beneath the wings, white ; scutellum flat, polished, with a large round 



