228 MEMOIRS ON THE COLEOPTERA 



pean Pentodon. In ponderosus the teeth of the maxillary galea 

 are long, subequal, very sharply pointed and sharply angulate 

 along their upper inner sides, while in snoivi, as representing the 

 clunalis type, they are thicker, decidedly more obtuse at apex, not 

 longitudinally carinulate and are more unequal, the outer tooth 

 being much shorter than the two inner. The lobes of the subapical 

 clypeal carina are frequently found worn entirely away, leaving 

 two scar-like surfaces surrounded by fine elevated rims, due to the 

 fact that the interior substance of the carina is softer than the 

 polished exterior surface, but at first it seems difficult to account 

 for the peculiar finely margined appearance of these eroded surfaces. 

 The above description of clunalis Lee., is derived directly from the 

 original and it will be observed that in the original descriptions of 

 both clunalis and snowi, the anterior impression of the pronotum is 

 said to be small, which could not be even approximately correct 

 language if the reference were to the thoracic impression of pondero- 

 sus; but it is probable, nevertheless, that Mr. Fall had ponderosus 

 in mind, and not the true chmalis,'m his description of Cheiroplatys 

 verticalis, which, however, because of the crenulated apex of the 

 hind tibiae, does not belong to this genus but to Xyloryctes, under 

 which it will be again brought to notice. 



Group II. 

 Subgenus Aztecalius nov. 



This subgeneric group has for its type the Orizabus isodonoides 

 of Fairmaire, abundant in the regions about the City of Mexico. 

 There are several species or subspecies, as can be seen from the 

 material in my collection, but, being unable to identify the typical 

 species of Fairmaire, it would be unsatisfactory to undertake any 

 differentiation of them at the present time. The female in this 

 subgenus is in appearance very unlike that of the female of Orizabus 

 proper, being strongly pyriform, almost exactly as in both sexes 

 of the genus Pseudaphonus; it was probably this that misled Mr. 

 Bates in assigning fairmairei (Pseudaphonus} to the genus Cheiro- 

 platys (Orizabus}. 



