230 PROCEEDINGS OF THE NATIONAL MUSEUM vol. i04 



the same subgenus with blacJcburnii, are radically different, particularly 

 in body shape and size. These differences become even more striking 

 when one includes the larval morphology in the comparisons. While 

 it is very difficult to separate the larva of G. splendidus from that of 

 blackburnii, the separation of ulkei is slightly more apparent and the 

 larva of egeriei is quite different from any of the above-mentioned 

 species. 



However, the larvae of several of the species remain to be discovered 

 and an}^ changes in the subgeneric concepts of Oeotrupes should be 

 delayed until the unknown larvae can be prociu-ed and studied. The 

 present subgeneric groupings as delimited by Jekel (1865) are Oeo- 

 trupes: stercorarius (Linne); Anoplotrupes : balyi Jekel, Aornn Blanch- 

 ard; Cnemotrupes: blackburnii (Fabricius), blackburnii excrementi 

 Say, egeriei Germar, opacus Haldeman, ulkei Blanchard ; Onychotrupes : 

 semiopacus Jekel, splendidus (Fabricius) , splendidus miarophagus Say. 



The ten native species and subspecies of North American Geotrupes 

 are quite diversified and the affinities of our species with European 

 or Asiatic species are not clear. Oeotrupes balyi and hornii appear 

 rather closely related to some of the European species. 0. stercorarius 

 (Linne), native of Europe and Asia, has recently become established 

 in Canada (Brown, 1940, p. 74), The other species are quite diver- 

 gent, with little resemblance to foreign species. 0. occidentalis Horn 

 is synonymous to laevistriatus Motschulsky, a Japanese species which 

 has evidentally not become established in this country. 



The North American species of the genus are quite variable (table 1) 

 in size, shape, and often in color, and because of this variation con- 

 siderable confusion has resulted in their nomenclature. Jekel (1865), 

 in his lengthy monograph, named from single specimens a number of 

 North American species, later synonymized by Horn (1868). Because 

 of my inability to examine Jekel's types, the present synonymy may 

 not be correct. However, I was able to personally examine the types 

 of LeConte, Horn, and Blanchard, and had specimens compared with 

 the Fabrician types, so the usage of the majority of names should be 

 reasonably acciu-ate. 



The range of the genus Geotrupes in North America is limited to 

 the states east of the Rocky Mountains, from southern Canada to 

 Mexico. 



Adult and brood habits of the species vary greatly and will be dis- 

 cussed for each species after the adult description. 



Key to the North American species of Geotrupes 



1. Elytra with strongly impressed striae 3 



Elytra with striae vaguely impressed or obsolete 2 



2. Color dull black, dorsal surface finely granulate (Indiana, Illinois, Kansas, 



