NORTH AMERICAN HYMENOPTERA. 193 



usual impressed line on anterior portion ; middle segment smooth, without an 

 enclosure; posterior face widely channeled down the middle, the lateral ridges 

 tolerably distinct; abdomen shorter than head and thorax united, ovate; py- 

 gidium acute at apex, convex hasally, depressed along the sides and on apical 

 portion. Black ; mandibles except apex, scape in front, tibiae and tarsi, yellowish 

 testaceous, the tibije darker within ; wings hyaline, iridescent, nervuresand stigma 

 black ; clypeus and lower part of inner orbits, with silvery pubescence. Length 

 about 3 mm. 



Colorado (Gillette). Its square head, smooth, subopaque head 

 and thorax and small size will easily distinguish it from the other 

 small, black species of Orabro. 



18. Group planijies. 

 Fore tarsi of S greatly flattened or distorted, i. e., the first joint 

 twisted ; otherwise as in group ater. Female unknown. 



79. Crabro planipes n. sp. 



% . — Anterior margin of clypeus subtruncate, or slightly rounded out in the 

 middle: head finely punctured, the front more distinctly so, and on occiput most 

 closely ; space between hind ocelli a little less than that between them and the 

 nearest eye-margin ; a strongly marked impressed line extends back from the 

 anterior ocellus ; im^jressed line extending from frontal depression well marked 

 and reaching the fore ocellus; first joint of flagellum a little longer than the 

 second ; pronotum rather higher above than in the other species of this group, 

 laterally obtusely angular ; dorsulum more strongly punctured than the front; 

 enclosure of middle segment well marked, basally with numerous, distinct, lon- 

 gitudinal strife, posterior face rugose toward apex, the lateral ridges strong ; fore 

 tarsi flattened, particularly the first joint; abdomen with microscopical punc- 

 tures, those on the last dorsal segment somewhat more distinct. Black, including 

 the mandibles ; scape in front, pronotum, tubercles, scutellum, fore femora, ex- 

 cept a narrow dark line behind, medial femora in front, fore tibiie except a line 

 behind, the medial and hind tibife except the apical two-thirds of posterior sur- 

 face, fore tarsi except a dark spot on first joint at apex and last two joints, medial 

 tai'si almost entirely, and basal half of first joint of hind tarsi, yellow ; clypeus, 

 inner orbits and cheeks and sides of thorax more sparsely with silvery pubes- 

 cence ; thorax beneath with longer, pale pubescence. Length 4 mm. 



Colorado. Agrees tolerably well with the description of G. Har- 

 risii Packard, but is evidently distinct. 



80. Crabro tarsalis n. sp. 



% . — Clypeus distinctly carinated, its fore margin with the medial produced 

 portion somewhat angular at apex ; vertex with fine punctures, those on the front 

 a little more distinct; space between hind ocelli much less than that between 

 them and nearest eye-margin ; impressed line extending from frontal depression 

 to fore ocellus feebler than usual, becoming obsolete just before the anterior 

 ocellus ; first joint of flagellum longer than the second ; the transverse apical 

 impressed line of pronotum is evident at the sides only, and before it, in about 

 the middle of pronotum is a short and stronger, impression, which gives the pro- 



TRANS. AM. ENT. SOC. XXII. (25) JUNE, 1895. 



