236 COLEOPTERA OF NORTH AMERICA. 



Sub-Tribe 1. — Lucailiiii (genuini). 



The typical g-enus is represented by three large species from 

 the Atlantic States, one of which {L. elajjhiis), by the very long 

 mandibles of the male, resembles the stag-beetle of Europe; and 

 one from New Mexico. Of Dorcus two species are found in the 

 Atlantic States; of Platycerus we have two eastern species, and 

 two from California and Oregon ; the mandibles of P. Agassti 

 are short in both sexes. The genera are thus distinguished: — 



Eyes strongly emarginated by the margin of tlie head ; 



Anterior tibise toothed on the outer edge. Lucanus. 



Anterior tibiae serrulate. Dorcus. 



Eyes almost entire ; sixth ventral segment visible. Platycerus. 



Sub-Tribe 2. — Cerucliiiii* 



One genus is represented in our fauna, Ceruchus, of cylindrical 

 form, with the head and mandibles of the male elongate. There 

 are three species, G. piceus from the Atlantic region, C. slrialas 

 and G. punctatus from Oregon. 



Sub-Tribe 3. — Siiiodeiidl-ini. 



This sub-tribe consists of but a single genus, Sinodendron, of 

 cylindrical form; the male has the head armed with a long horn, 

 and the anterior part of the thorax suddenly declivous; the man- 

 dibles are short in both sexes; the eyes are not emarginate; the 

 maxilUe and ligula are not concealed by the mentum. 



S. i'ugosum Mannh. inhabits California and Oregon. 



Tribe II.— PASSALIXI. 



Ligula large, corneous, filling a quadrate emargination of the 

 mentum; antenna? straight, first joint of moderate length; man- 

 dibles with a basal molar tooth, and an anterior movable one; 

 maxillae with both lobes hooked; labrnin not connate; scutellnui 

 in front of the base of the elytra; middle coxfe nearly globular. 



This tribe contains but a single genus, of which many species 

 exist in the warmer parts of the earth ; it is represented in our 

 fauna by but one. Passably corvutvs, an elongate, somewhat flat- 

 tened, shining beetle, of large size, having the head armed with 

 a short bent hook, and the elytra deeply striate. It is quite 

 frequently seen in old stumps of trees. 



