STUDIES ON THE NORTH AMERICAN 
REPRESENTATIVES OF 
EPHEBOMYRMEX (HYMENOPTERA : FORMICIDAE) 
By W. S. Creighton 
Department of Biology, City College, New York. 
Pogonomyrmex (Ephebomyrmex) imberbiculus was de- 
scribed by W. M. Wheeler in 1902 and seven years later 
he added the descriptions of pima and townsendi. Since 
that time there has been surprisingly little additional in- 
formation published on these interesting ants. What has 
appeared has consisted largely of locality records, but 
few of these have added much to our knowledge of the 
ranges of these insects. It is gratifying to be able to 
present a more complete picture of the distribution of 
our representatives of Ephebomyrmex, particularly since 
this clears up certain questions related to the taxonomic 
status of townsendi. It has also been possible to expand 
Wheeler’s account of the habits of imberbiculus, for it 
appears that these same habits are true of pima also. 
In past years the writer has been able to study 53 colonies 
of Ephebomyrmex at 40 stations. This study has shown 
that the ranges of both imberbiculus and pima are much 
more extensive than was formerly supposed. It has also 
shown that townsendi is a synonym of imberbiculus. 
Wheeler described townsendi in 1909 (1) on the basis 
of a single specimen from Chihuahua. It is hard to avoid 
the suspicion that one of Wheeler’s reasons for giving 
townsendi specific status is the fact that the type specimen 
came from Mexico. Certainly the structural features 
which distinguish townsendi from imberbiculus are not 
particularly impressive. They consist mainly of the sculp- 
ture of the postpetiole and the first gastric segment. 
Wheeler believed that in imberbiculus the postpetiole is 
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