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 

 followfing 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 



Vv'ith 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. 



PostericJr 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 

 l)ase 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. 



