ART. 1 AMERICAN WASPS OF THE GENUS SCELIPHEON PORTER 3 



caenientanxiin present no essential differences, supporting the belief 

 that the whole series constitutes but a single species. Those of jls- 

 tulare and fasciatum are plainly distinct. Those of lucae are some- 

 what similar to those of caeinentariuTii^ but these two species are evi- 

 dentiy distinct because of other differences. The genitalia of as- 

 Hniilis are distinct from those of cae?nenfaHuni, proving that as- 

 siinilis is not a variety of caementanum^ as it was considered by 

 Kohl who described this form under the name nicaraguanuin. 



CLASSIFICATION AND ANALYTICAL KEYS 



The genus Sceliphron belongs, according to Comstock -, to the 

 Sphecinae, one of the six subfamilies into which his family 

 Sphecidae is divided, but the subfamily Sphecinae of Comstock is 

 equivalent to the family Sphecidae of Ashmead. For the present 

 paper the classification of Ashmead is adopted, and the following 

 key to the subfamilies of the family Sphecidae is that proposed by 

 him ^ and later used by Fernald in his Digger Wasps of North 

 America ^ ; the groups here given subfamily rank are considered 

 tribes by Comstock. 



Following the key to the subfamilies is a key to the genera of 

 the Sceliphroninae, also taken from Ashmead.^ 



KEY TO SUBFAMILIES OF SPECIDAE 



1. Second cubital cell receiving only the first recurrent vein ; the second recur- 



rent vein received by the third cubital cell, or at least beyond the second 

 transverse cubital. (Both recurrent veins are received by the first cubital 



cell in a few extra-limital forms) 2 



Second cubital cell receiving both recurrent veins, or the second recurrent 

 vein is interstitial with the second transverse cubitus, although sometimes 

 the first recurrent is interstitial with the first transverse cubitus or then 

 received by the first cubital cell 3. 



2. Antennae inserted on the middle of the face ; claws with one to six teeth 



beneath ; tibiae strongly spinous, or at least never with weak or feeble 

 spines; tarsal comb in female present (except in Isodontia) 



Chlorioninae (Sphecinae Authors). 



Antennae inserted far anterior to the middle of the face; claws, simple, 



without teeth, or at most with a single small tooth near the middle ; tibiae 



smooth, not spinous ; tarsal comb in female never present Podiinae. 



3. Claws simple, without a tooth beneath ; tibiae more or less spinous, tarsal 



comb in female present ; abdomen most frequently very elongate, the 

 petiole composed of two segments, rarely of only one segment ; cubital 

 cell of hind wings usually originating beyond the transverse median vein. 



Sphecinae (Ammophilinae Authors). 



2 Comstock : An Introduction to Entomology, 1924. Classification of the family 

 Sphecidae, pp. 962-972 ; account of subfamily Sphecinae on pp. 966-967. 



3 Ashmead: Can. Ent., vol. 31, 1899, pp. 347-352. 



^ Fernald : Digger Wasps of North America, Proc. U. S. Nat. Mus.. vol. 31, 1906. p. 308. 

 » Ashmead: Can. Ent., vol. 31, 1899, p. 352. 



