314 OEO. H. HORN, M. D. 



Our spcoies may be divided into four subgeneric groups, cbaracter- 

 ized as follows : — 



Thorax dissimilar anteriorly in the two sexes. 



Elytra connate: body apterous, metasternum short Mycotrupes Lee. 



Thorax similar % 9- elytra free. 



Antcnnte with the second joint of club normal. Apical 

 tootli of anterior tibia prolonged internally in % , 

 simple 9 • 



Middle tarsus 'J, short, thick Onychotrupes Jekol. 



Middle tarsus '^normal Cnemotrupes Jekel. 



Antennas with the second joint of club truncate or 

 emargina'e, so as to be hidden at some point when 

 the club is closed. 

 Apical tooth of anterior tibia similar % 9 Anoplotrupes Jekel. 



]Mycotri)pes Lee. 



This subgenus forms a very natural transition between the two 

 ('Ik lotrupcs Jekel and Thorcctcx Mulsant, agreeing with both in the 

 connate elytra and short metasternum, though differing from either 

 in the form of the thorax. In the male the thorax has a broad trans- 

 verse exeavation, the fenjales have a very well marked longitudinal 

 grove with a shallow exeavation on each side. The thorax is strongly 

 sinuous at base and without margin. The head of the male is strong- 

 ly tuberculate, and iu one specimen prolonged into a horn. The ely- 

 tra are not striate but ornamented with small granules in a manner 

 similar to some of our species of Canthon. The anterior tibia has the 

 apical tooth prolonged internally % ; the middle tarsus is normal S 9 ? 

 though longer in the % . 



But one species is known in this group, refusus Lee. (Proc. Acad. 

 1366, p. 381,) long known under the same name, though unpublished, 

 by MacLeay, and distributed in some European collections by Major 

 Lec.onte as fungivorus. It was unknown to Jekel, who thought it 

 might possibly be synonymous with the opacus of Haldeman. It may 

 be readily distinguished from any other Geotrupes by the characters 

 above given, and the more easily from our own species by its short 

 metasternum and connate elytra. It is found in our southern states 

 feeding in fungi or under dried animal matter. 



Onyciiotrupes Jekel. 

 Several of our largest and most prominent species enter into this 

 subgenus. It is characterized by a great thickening of the middle 

 tarsus. The first four joints are shorter than broad (S ), the last be- 

 very thick, with the two claws also much thickened and suddenly re- 



