NOKTII OF MEXICO. 



371 



Middle plate of mentum transversely oval; interstrial 



spaces of elytra densely punctulate. p U n c t ula t a. 



Last joint of antennse oblique, pointed. i m her bis. 



Epistoma deeply emarginate. 1 on gul a . 



Lower edge of anterior femora with a broad fossa near the tip, and 



slightly emarginate. m entails. 



The groove of the lower edge of the anterior femora differs but little in the first five 

 species, and is limited anteriorly by a ridge extending from the base to the apex, so that 

 the lower rd^r of the femur when viewed from the front is very nearly a straight line. In 

 the last species however, the channel is replaced by a broad fossa rather deeper than the 

 groove in the other species, defined anteriorly by a ridge, not extending to the base, which 

 when viewed from the front appears emarginate near the apex of the lemur. The remain- 

 ing characters in the table are sufficiently plain to be readily recognised. 



IT. impressa, Mela., Froc. Aoad. 8, 64 



Our largest species, and for a long time considered identical with the European cult- 

 naris, from which it differs by its larger size and different sculpture of mentum (See Le- 

 conte, New Species, p. 123). 

 Length .4(i inch. 



Occurs abundantly everywhere in the Eastern and Middle States. 

 U. iniberbis, Leo., New Species, p. 13;i. 



Similar in form and sculpture to the preceding, differing however, in the transverse 

 middle plate of mentum and the form of the last joint of the antemnc. 

 Length .3 2-. 3 6 inch. 



Occurs Avith the preceding, but less common, more abundant in the Southern States. 

 U. mentalis, n. sp. 



Similar in form and sculpture to imberbis, but differs in having a rather less robust 

 form and a stouter thorax. The terminal joint of the antennae is rounded at tip, not 

 oblique. The; anterior femur has near its apex a rather broad fossa replacing the entire 

 groove of the other species. The edge does not extend from apex to base, and is not a 

 straight line, but sinuous at the position of the fossa. The middle plate of mentum is 

 deeply concave, smooth and shining, with the edge somewhat thickened in the male (fe- 

 male not seen). The epistoma, is more nearly truncate than any other of our species. 

 Length .34 inch. 



Two specimens from Texas and Kansas. 

 U. longula, Leo., Proc. Acad. 1801, p. :;:>;!. 

 More elongate and parallel. Epistoma deeply emarginate. Anterior femur grooved, 



