86 Dr. A. S. Packard, Jr's Revision of the 



by the remarkably square bead and front, which does not as usual 

 round inwards towards the insertion of the mandibles. It is less hirsute 

 than C. singular is. 



Crabro smgularis, Smith. 



C. singularis, Smith, Cat. Hym. Br. Mus. iv. p. 417. % . (1S56.) 



% . Head black, finely punctostriated, with a slight pubescence in 

 front and on the sides, a line of silvery pubescence on the orbits, as in 

 the clypeal region. Antennae long and slender, scape long, slightly 

 angulated, sub-clavate, yellow, with or without an ovate dark spot on 

 the inside; flagellum black; joints very long, especially the second, 

 which is fully one-half as long as the scape; third joint arcuated, 

 dentate beneath, terminal joint long obconic. 



Thorax black, finely punctured, meso-scutum finely striated, flanks 

 pilose, concealing the sculpturing on the propodeum, especially dense 

 on the anterior flank. On each half of the prothorax is a yellowish 

 irregular yellow spot; tubercle yellow; meso-scutum black, bipunctate 

 with yellow. Trochanters black, femora pale yellow, dilated and flat- 

 tened with a stout spine at base externally, and provided with a thin 

 brush of fine hairs ; tibiae pale, straw yellow ; tarsi concolorous, termi- 

 nal joint and ungues black. Middle pair of legs entirely black, except 

 the basal joint of the tarsus which is straw yellow, and there are two 

 minute parallel yellow streaks on the outer side of the tibiae. Hind 

 trochanters and femora black; tibiae yellow, black at tip ; basal joint 

 of the tarsus yellow, black at tip, remaining joints black. 



Abdomen shiny black, with ten or twelve lateral fasciae, of which 

 the first pair are much the largest, approaching one-half nearer the 

 median line of the body than the succeeding pair, which are one-half 

 as large and elliptical in form; the last pair small, linear; all are ob- 

 lique, and placed on the front margin of each ring, tips black, termi- 

 nated by a few hairs. Beneath black as usual. 



Length of body, .50; head and thorax, .20; abdomen, .24 inch. 

 9 . Head very square in front and unusually large. Body very 

 black, shiny, very finely puncto-striated, and free from pubescence, ex- 

 cept on the flanks of the thorax. Head very finely punctulated, not 

 striated; no pubescence in front; eyes as usual, finely lined with a 

 silvery pubescence; clypeus black, covered with a golden pile, while 

 on each side it is silvery; mandibles yellow, black at base and tip. 

 Antennae with the scape entirely yellow, remaining joints black. 

 Thorax finely striated, a large, disconnected, yellow stripe on the pro- 

 thorax ; tubercle yellow; on meso-scutellum a geminate spot, some- 



