662 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



Key to Genera. 



1. Mandibles simple, acute at apex Lindenius p. 664 



Mandibles truncate, bidentate or tridentate at apex 2 



2. First abdominal segment petioliform or abdomen distinctly 



petiolate Rhopalum p. 664 



Abdomen sessile or subsessile 3 



3. Mesepimeron with a strong carina following the second 



pleural suture; mesepisternum strongly sculptured with 



some form of striation . ., Solenius p, 664 



Mesepimeron without a strong carina; mesepisternum not 

 strongly sculptured, usually only punctate Crabro p. 669 



The following two species are too imperfectly known to be 

 classified according to the above system. In the hope that they 

 will be rediscovered and redescribed to harmonize with our pres- 

 ent views of the classification of this group, the original descrip- 

 tions are here given. 



Crabro oblongus Packard. Proceedings Entomological 



Society of Philadelphia, Vol. vi, p. 88. 



" Female. Closely allied to C. singularis, head of much the same 

 proportions, but narrows a little behind, and is throughout narrower 

 as the entire body is. Eyes a little nearer together; the convexity of 

 the vertex and the grooving of the front the same as in C. singularis. 

 Antennal groove well marked, polished, on each side a narrow edging 

 of silken pubescence; clypeus golden as in C. singularis, but the hairs 

 are much finer, the lateral lobes are more triangular and silvery; 

 mandibles black, with the middle wedge-shaped area twice grooved 

 towards the base, where in C. singularis it is smooth; palpi slender, 

 joints much longer and slenderer by one-third than in the other 

 species above named. Antennae as in C. singularis, scape entirely 

 yellow, hardly as stout, joints of flagellum a little stouter. Two 

 square, yellow spots on the prothorax; lateral tubercle yellow; meso- 

 thorax entirely black above with no yellow markings; surface of the 

 scutum finely striated; scutellum and metascutellum highly polished. 

 Propodeum much as in C. singularis, but the mesial furrow widens at 

 base, with similar lateral and transverse rugae; legs colored much the 

 same; within the hind tibiae a dark stripe. Abdomen long, sides 

 unusually parallel, giving it an oblong shape; with ten yellow fasciae, 

 those in the basal joint being simply dots, those in the second ring 

 much larger than the succeeding ones, not wedge-shaped, but elliptical; 

 beneath very convex; tip one-half as long as in C. singularis, the 

 enclosed triangular upper surface much longer and narrower than in 

 the allied species. 



"Length of body, .64; head and thorax, .33; abdomen, .31 inch. 

 Conn. (Norton). 



