Fossorial Bt/menoptera of North America. 307 



the three succeeding segments is a transverse yellow band, indented on 

 the median Hue; tip brown-black, slightly hirsute. Beneath black, 

 with two large, yellow patches on 3d and 4th rings, separated on the 4th, 

 and confluent on anterior portion of 3d. 



Length of body, .30; head and thorax, .10; abdomen, .20 inch. 

 9 . Besides the usual sexual differences, the 9 differs in having 

 the yellow band on the prothorax wider on the sides, two angular spots 

 on flanks of mesothorax, posterior one oblong, and the anterior one. or 

 tubercle, triangular as usual. The mesoscutellum is almost entirely 

 yellow; fore femora black, yellow at tips; middle trochanters black, 

 yellow at tip; femora black, yellow at tip, tibite yellow; tarsi yellow, 

 brownish towards the ungues; hind legs black, except the tibiae, 

 which are testaceous towards the tips, with a blackish spot on the upper 

 sides towards the tips. 



Length of body, .30; head and thorax, .18; abdomen, .18 inch. 



Illinois, (Coll. Ent. Soc. Phil.) 



Differing in the additional spot on the flanks behind the tubercle, 

 and the yellow scutellum and black legs, the 9 i s referred with some 

 hesitation to this species. 



This species may easily be known by its slender habit ; the fore 

 tibiae are scarcely dilated; and there is a brush of hairs replacing the 

 vexhillum, and the upper side of the basal joint of the abdomen is 

 surrounded by a yellow band, while the remaining spots are broader 

 and heavier than in any of the other species. 



Thyreopus monticola. n. sp. 



9 . Head shorter and broader than in the preceding species; eyes 

 shorter and smaller, and much farther apart, so that the front is much 

 broader and larger than usual ; ocelli arranged in a curved line in 

 a low triangle; antenna! groove not well marked, no pubescence on the 

 orbits; in front of the ocelli are a few sparse brown hairs ; surface 

 distinctly puncto-striated ; head rounding in front towards the inser- 

 tion of the mandibles; clypeus one-half as long as broad, being short 

 and broad, slightly carinated, lateral lobes broad but short, silvery. 

 .Mandibles large aud heavy, slightly bidentate, but the upper tooth is 

 nearly obsolete, so that it is almost unidentate. Antennae rather long 

 and slender, scape large, clavate, more than usually thick at the ex- 

 tremity, yellow, brown at base and tip on the upper side; flagelluni 

 long and slender, black. 



Prothorax yellow above, the two fasciae slightly separated; meso- 

 scutum distinctly furrowed in the mesial line, while the submesial 



