222 MEMOIRS ON THE COLEOPTERA 



stated, as it is under Aphonus castaneus further on; the male, 

 having a partially smooth and discretely punctate pygidium, un- 

 doubtedly indicates an alliance with the jet-black aterrimus from 

 the colder parts of New England, and it may be placed near that 

 species in the table. 



Orizabus Fairm. 

 Cheiroplatys Bates nee Hope. 



It seems better to retain this name for certain American Pento- 

 dontids described by Fairmaire, LeConte and others, and not to 

 transfer the species to Cheiroplatys, as suggested by Bates in the 

 Biologia; we have the testimony of Lacordaire and Fairmaire 

 that the two genera are different, though closely allied, and my 

 observations on the maxillary galea show that there is no marked 

 accordance with the form of that organ in Cheiroplatys as described 

 by Burmeister. The body is stout and oblong or ovoidal, strongly 

 convex, the head small, the clypeal carina placed well behind the 

 actual clypeal apex as in Aphonus and the frontal prominence is 

 variable in form but never very conspicuous. The mentum is 

 strongly punctured and setose and its moderately narrowed ligular 

 part is sharply angulate and slightly deflexed at tip, the angle 

 fitting loosely into a deep emargination of the short thick labrum. 

 The mandibles are small, thin, laminate, slightly concave, more or 

 less ciliate on the rounded and edentate outer margin and are 

 completely hidden as a rule; only when widely open, can they be 

 seen protruding slightly at the sides of the clypeal apex. The 

 post-coxal process of the prosternum is very densely setose through- 

 out as in Ligyrus and the sterna are similarly conspicuously 

 pubescent. 



There has been considerable divergence of opinion regarding the 

 maxillary galea, LeConte and others observing that the apex is 

 bidentate, while each of these apical teeth is declared to be duplex 

 by Bates. There are only very few of my examples in which the 

 galea is exposed and in these the tip is rather plainly tridentate as 

 in Ligyrus, but the three teeth are not in the same plane, the plane 

 of the outer two making a considerable angle with that of the inner 

 two, so that at certain angles only two teeth can be seen. 



Although allied to Aphonus, this is a very isolated generic type 



