2 HYMENOPTERA OF AMERICA. [PART I. 



general appearance, which is much more easily detected than 

 described. 



The habits of the Vespidse are quite different; some being 

 social, some solitary, living by rapine, and some parasitic. 



These three moral tendencies correspond to the special forms 

 which characterize the groups, into which we have separated the 

 following subfamilies: — 



I. Masarinjb, or Parasitic Wasps. — Wings having an indistinct duplica- 

 tion. Antennae sometimes enlarged into a club, their last articles often 

 soldered together. Prothorax generally convex before. Scute! superposed 

 upon postscutel. Claws of tarsi generally unidentate ; posterior and inter- 

 mediate tibiae terminated by two articulate spines. Lip quadrifid or bifid. 



Wings having but three cubital cells. Eyes slightly emarginate. 



II. Eumenin-S or OPYNEKiyjE. 1 or Solitary Wasps. — Wings having a more 

 distinct duplication, always offering four cubital cells. Antennae subfili- 

 form, with the articles distinct. Lip lengthened, quadrifid. Claws of the 

 tarsi unidentate. 



III. Vesting, or Social Wasps. — Having the same characters as the 

 Eumeninae, but the claws of the tarsi not toothed; the wings always 

 having a very distinct duplication; the lip short, quadrilobed. 



The Masarinse can easily be distinguished by the inner neura* 

 tion of their wings, etc. ; but the solitary and social wasps pre- 

 sent so few distinctive general characters, that they are always 

 puzzling. It will hardly be deemed superfluous to give here a 

 table of empirical characters which may assist iu distinguishing 

 them in every case. 



1 In my "Etudes sur la Famille des Vespides" I have given to this tribe 

 the name of Eumeniens (Eumeninat), after the oldest genus of the tribe. 

 But as the genus Odynerus is much more important, and as the tribe 

 Vfspince is named after a sessile genus, I have thought best to adopt in 

 preference that of Odyneriens (Odynerince) for the sake of conformity in the 

 names of both tribes. 



