326 



REVISION OF THE TENEBRIONlDiE. OF AMERICA, 



more enlarged than the posterior femora. The anterior tibiae are alone denticulate on the 

 inner margin. The species have black legs, are three in number, and may be distin- 

 guished as follows : 



Hind femora ^ denticulate, one tooth slightly longer. 



Epistoma prolonged, excavate beneath. concolor. 



Hind femora % armed with a long acute tooth. 



Elytra with rows of large punctures, interstices flat. cr i b r a t u s . 



Elytra with rows of small punctures, interstices alternately 



more elevated. costulatus. 



E. concolor, Lea, Ann. Lye. V., p. 143; Thomson, Arcana 1, pi. xii, fig. 3. 



The largest species of the genus. It may be; known by the armature of the hind 

 femora of the male, the more prolonged and excavated epistoma. The elytra arc oval, 

 broader at or behind the middle, and the surface marked with rows of large faintly im- 

 pressed punctures, of which the interstices arc scarcely convex. The outer joints of the 

 antenna; are less transverse than in the following species. The thorax is also more deeply 

 emarginate at base. 



Occurs on the borders of the Colorado Desert, and in the northern end of the Penin- 

 sula of Lower California. 



Length .70-.94 inch. 



C. eribratus, Lee, Proc. Acad. 1801, p. 337. 



With the same genera] form of the preceding species, this one has the thorax less 

 narrowed behind and less emarginate at base. The elytra are oval, broader in front of the 

 middle. The rows of large punctures are arranged in pairs. Near the apex of the elytra 

 the interspaces between the second and third, and sixth and sevanth rows are elevated 

 and confluent, and form on each elytron a very prominent tubercle. The outer joints of 

 the antennae are more transverse than in concolor. The hind femora of the males are 

 armed with a rather long acute tooth, the females arc unarmed. 



Occurs at the extremity of the Peninsula of Lower California. 



Length .50-. 70 inch. 



C. costulatus. Black, sub-opaque; thorax sub-quadrate, slightly longer than broad and somewhat narrower 

 behind; apex truncate, base feebly emarginate, hind angles rectangular; sides rounded in front, straight behind the 

 middle. Elytra elongate oval, wider in front of middle; surface striate, striae with coarse feebly impressed punctures, 

 interstices elevated, sub-acute, alternately larger, the first and third of the larger costre confluent near the apex, form- 

 ing a, slight elevation. 



Hind femora of males with an acute tooth. 



This species bears a very close relationship to the preceding, though abundantly dis- 

 tinct. The thorax is more quadrate and much more distinctly punctured. The antennae 

 have the last five joints very transverse, more than twice broader than long. 



