Coleopterological Notices. 485 



shining and not granulose, with much less robust femora and de- 

 cidedly less clavate and spinose posterior tibiae. In dehilis the pro- 

 notum is finely but distinctly punctate and the elytral strife are 

 more feebly impressed at base, the elytra being exactly equal* in 

 width to the prothorax. 



In gracilipes the wings are very well developed, being much 

 longer than the elj'tra. 



PLATYDEMA Cast. 



There are two species of this genus which are commonly con- 

 founded under the name excavata Say. One of these forms was 

 recently described by me, from an abnormally small specimen, under 

 the name parvula, and as Say's description will apply equally to 

 both, the type being no longer in existence, I have thought it 

 desirable to give differential diagnoses of the two species under 

 names which have been already published ; they may easily be 

 separated by the following characters which are taken from the 

 males : — 



Form narrowly oval ; eyes moderate ; frontal excavation very large and deep, 

 the horns separated by a distance which is equal to one-half the entire 

 width ; elytral intervals very minutely and sparsely punctate ; femora 

 sparsely and finely punctate throughout excavata 



Form broadly oval ; eyes much larger ; frontal excavation small, moderate in 

 depth, the horns separated by scarcely more than one-third the entire 

 width ; elytral intervals more convex, more strongly and densely punc- 

 tate, the striae rather more deeply impressed ; femora finely, ratlier more 

 densely punctate, especially toward apex parTllla 



In addition to the characters given it should be stated that the 

 frontal horns themselves are quite different in form ; in excavata 

 they are much longer and are perfectly straight, while in par\:vla 

 they are shorter, stouter, more gradually acuminate from base to. 

 apex, and are arcuate and curved upward throughout their length. 



The type of opacula appears to be a small and rather abnormal 

 specimen of ruficornis Sturm ; the head is more coarsely punctate 

 than usual, but otherwise I can find no good character to distin- 

 guish it. 



