No. 22.] HYMENOPTERA OF CONNECTICUT. 643 



SO common throughout the United States. Many of the species 

 are closely related, and care must be taken in determining them. 



The species of this subgenus, as far as known, build their nests 

 within the ground. 



Key to Species. 



1. Black and white consobrina 



Black and yellow 2 



2. Black spot of first dorsal abdominal segment in the form of 



a lozenge; scape black germanica 



Black spot of first dorsal abdominal segment in form of a 

 triangle, or transverse 3 



3. Base of first dorsal abdominal segment black, with a black 



point in middle of the yellow posterior margin vulgaris 



First dorsal abdominal segment yellow, with a transverse 

 black spot; scape sometimes entirely black communis 



V. (V.) consobrina De Saussure. 



Occurs throughout the State. Branford, 24 August, 1904 (P. 

 L. B.) ; North Haven, 3 August, 1905 (B. H. W.). 



V. (V.) germanica Fabricius. Howard, Insect Book, PI. 

 vi, Fig. 24. 



Occurs throughout the State. Many specimens from New 

 Haven (B. H. W., H. L. V., P. L. B., W. E. B., E. J. S. M.) ; 

 Branford (H. W. W.) ; Mount Carmel (E. J. S. M.). 



°V. (V.) communis De Saussure. 

 Sure to be found within the State. 



V. (V.) vulgaris Linnaeus. Howard, Insect Book, PI. v, 



Fig. 13. 



Occurs throughout the State. New Haven, June, 1905 (B. H. 

 W., A. H. Pierson, J. A. Howarth, Jr.) ; Branford, August, 1905 

 (H. W. W.) ; Prospect, 15 August, 1906 (W. E. B.). 



POLISTINI. 



Polistes Latreille.* 

 The species of this genus make nests with exposed cells. 

 They are known to be predaceous, and at least one species takes 

 its victim without first stinging it. They may use old nests, and 

 are said to study a locality to get their bearings. 



•Copied from Mr. Viereck's manuscript. 



