No. 22.] HYMENOPTERA OF CONNECTICUT. 665 



4. Mesoscutum striato-punctate, anteriorly transversely, poste- 



riorly longitudinally Lophocrabro p. 667 



Mesoscutum not striato-punctate 5 



5. Abdomen indistinctly punctate or impunctate Xestocrabro p. 667 

 Abdomen distinctly punctate 6 



6. Female pygidium flat, triangular; fore tarsi of male strongly 



flattened Protothyreopus p. 668 



Female pygidium narrow, strongly excavated; fore tarsi of 

 males not or scarcely flattened Hypocrabro p. 668 



Subgenus Clytochrysus Morawitz. 

 Only one species of this group has been recorded from Con- 

 necticut, but another one, according to its distribution, may occur 

 within the confines of the State. The following table will separate 

 these two species : 



Key to Species. 

 First joint of flagellum, in female, fully as long as three 

 following united; first and second joints of flagellum, in 

 male, more strongly dentate than third and fourth; fore 



femora of male black and yellow obscurus 



First joint of flagellum, in female, scarcely as long as three 

 following united; first four flagellar joints, in male, with 

 teeth subequal; anterior femora of male rufous, striped 

 with yellow and black nigrifrons 



S. (C.) obscurus Smith. 



New Haven, 8 July, 1904 (P. L. B.) ; Colebrook, 21 July, 1905 

 (H.L.V.). 

 S. (C.) nigrifrons Cresson. 



Subgenus Solenius LePeletier (s. str.). 

 The two species which belong to this group and occur in the 

 eastern United States may be separated as follows : 



Key to Species. 



Posterior face of propodeum completely transversely striato- 

 reticulate; scape of male angulate near apex; first three 

 flagellar joints of male largest, so flagellum is thicker at 

 base producticollis 



Posterior face of propodeum with a strong median channel 

 and longitudinally striato-reticulate along it; scape and 

 flagellum of male normal interruptus 



S. (S.) interruptus LePeletier. Howard, Insect Book, PI. 

 iv, Fig. 6. 



