326 REVISION OF THE TENKISHIONID-K OF AMERICA, 



more enlarged than the posterior femora. The anterior tibiae arc 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 tenth slightly longer. 



Epistoma prolonged, excavate beneath. concolor. 



Hind femora :■ armed with a long- acute tooth. 



Elytra with rows oflarge punctures, interstices flat. cribratus. 



Elytra with rows of small punctures, interstices alternately 



more elevated. costulatus. 



E. concolor, Lee, Ann. Lye. ST., p. 143; Thomson, Arcana 1, pi. xii, Ii<;. 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 are oval, 

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

 pressed punctures, of which the interstices are 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 .10-. 94 inch. 



('. cribral us, Lee, Proc. Acad. 1861, p. 337. 



With the same general term of the preceding species, this one has the thorax less 

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

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

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

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

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

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



Occurs at the extremity of the Peninsula of Lower California. 



Length .50— .70 inch. 



C. cost ulal us. Black, sub-opaque; thorax sub-quadrate, slight!} longer than broad and somewhat narrower 

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



middle. Elytra el jate oval, wider in front of middle; surface striate, stria; with coarse feebly impressed punctures, 



interstices i l< rated, sub-acute, alternately larger, the lirst and third of the larger costaa confluent near the apex, form- 

 ing a slight elevation. 



Hind femora of males with an acute to »th. 



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

 tinct. The thorax is mure quadrate and much more distinctly punctured. The antennas 

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



