AMERICAN COLEOPTERA. 127 



One specimen, Colorado River, California. The antennae and tibiae 

 are testaceous at base. 



The specimen from which the above description was drawn is a 

 female and remains unique. It does not resemble any of the genera 

 in our fauna. The form of thorax is that of Endeodes or Temnopso- 

 phus. I prefer calling attention to it as of a doubtful genus to plac- 

 ing it (with views to the contrary) in any genus in our fauna. 



The It III-: VI'll 1 1> . 1-1 or the United States. 



BY GEORGE H. HORN, M. D. 



The species are few within our faunal limits, and no territory in 

 the world of equal size is probably as poorly represented in this family. 

 One species only inhabits the United States and the portion of the 

 Continent to the north, the remaining species being from the penin- 

 sula of Lower California and resemble those from the adjacent regions 

 of Mexico, and are inserted in the present paper to render our know- 

 ledge of the fauna of that region more complete. 



Two genera occur in our fauna, representing two groups as defined 

 by Lacordaire. 



Thorax convex above, not channelled Kupsalis. 



Thorax depressed, deeply channelled Itreiitlius. 



EUPSAL.IS, Lac. 



Lacordaire, Genera vii.. p. 430. 



This genus represents the Arrhenodides of Lacordaire, distinguished 

 by the conical thorax not compressed in front, the antennae moder- 

 ately robust, but not terminated by a club. Head transverse, mandi- 

 bles prominent. Among the genera of the group, Eupsalis is known 

 by its short and broad rostrum, the broad head, the femora slender 

 and cylindrical at base. It is closely allied to Arrhenodes, in which 

 our species had been placed, but differs by the hind angles of the 

 head being effaced, and the surface shining. 



E. maxillosus, Oliv. (Brentus) Ent. v. 84, p. 443, No. 17, pi. 1, fig. 1. c % , 

 also, pi. 2., fig. 17, a % , b $. Lac. {Eupsalis) loc. cit; septe.ntrion.is Hbst., 

 {Brentus) Col. vii., p. 183, No. 5, pi. 107, fig. 5, % . — Color variable from nearly 

 black to rufous. Thorax oval slightly longer than broad, apex truncate, sides 

 gradually divergent, base constricted ; surface smooth convex, very sparsely 

 punctulate. Elytra robust, more than twice as long as wide, slightly narrow- 



