THE NORTH AMERICAN BEES OF THE GENUS NOMIA. 



By T. D. A. Cockerell, 



Of the University of Colorado, Boulder. 



For many years past the National Museum has possessed a series 

 of undescribed species of the genus Nomia, to which Dr. W. H. 

 Ashmead gave manuscript names. In the new catalogue of bees 

 now in preparation I was anxious to cite these names, but as their 

 esteemed author unhappily never found time to prepare descriptions, 

 I asked for the loan of the material in order to publish the necessary 

 diagnoses. While giving these, I have thought it useful to arrange 

 the species into groups and cite all those belonging to our fauna. 



At the outset the question arises as to the number of genera to be 

 recognized. Doctor Ashmead, in 1899, divided the Nomia of authors 

 into Epinomia Ashmead, Nomia Latreille, Paranomia Friese, and 

 Mould Westwood (Eunomia Cresson). Monia, however, is really aCol- 

 letid, and since Eunomia is preoccupied it takes the name Dit unomia 

 Cockerell." Other segregates are the African Crocisaspidia Ashmead 

 and Stictonomia Cameron, and the Asiatic HoploTiomia Ashmead 

 (type //. quadrifasdata Ashmead). 



The common usage in the United States has been to recognize two 

 genera, Nomia and Eunomia (Dieunomia) . It is not quite clear 

 whether Nomia can be usefully split up into a number of genera, but 

 at present it seems better to regard all the American forms as per- 

 taining to a single genus with several named subgenera. The type 

 of Nomia is the European N. diversifies Latreille, of which 1 have 

 specimens from Doctor Friese. This is a strongly punctured insect, 

 with very large tegulse and curious laminate tubercles. It represents 

 a subgeneric group (Nomia, s. str.) not found in America. N. ruficor- 

 nis Spinola belongs to the same subgenus, which is also characterized 

 by a backwardly-directed tooth at each side of the scutellum in the 

 male. N. rujicornis has what at first sight seem to be white tegu- 

 mentary bands on the abdomen, but they are really bands of dense 



" Entomologist . vol. 32, p. 11. 



Proceedings U.S. National Museum, Vol.. 38— No. 1745. 

 Proc.N.M. vol.38— 10 19 289 



