226 MEMOIRS ON THE COLEOPTERA 



Fabr.) I have not seen, but it probably does not occur in Cuba, most 

 of the Coleopterous species of these two islands being different. 



The subbasal internal mandibular tooth broadens out greatly in 

 the shorter mandible of the less developed males, becomes more 

 obtuse and occupies much more of the internal margin. 



Aplagiognathus Thorns. 



The chief characters of this genus as stated by Thomson (Ess. 

 Class. Ceram., p. 320), are the moderate mandibles, which are sub- 

 vertical in both sexes and the sides of the prothorax either multi- 

 spinose or crenate and posteriorly dentate; some eight species were 

 named by Lacordaire as belonging to the genus, or section of Mallodon 

 as he preferred to regard it, forming a very heterogeneous mixture, 

 beginning with spinosus Newm., which was adopted definitely 

 as the type of Aplagiognathus by Thomson and including the female 

 of Mallodon dasystoma Say, as well as melanopus, cilipes and other 

 notably dissimilar forms of more northern distribution. 



In the "Biologia," Mr. Bates describes an Aplagiognathus in 

 the sense of Thomson as indicated by his chosen type, under the 

 name hybostoma, which he states is closely allied to spinosus, and 

 the figure portrays mandibles, short to be sure, though apparently 

 not subvertical at all but virtually horizontal, and they are described 

 as being "rufo-hirtis." The species described below under the 

 name guatemalensis also has short male mandibles, which are 

 however perfectly horizontal, thus contradicting the very ety- 

 mology of the name Aplagiognathus, densely rufo-pilose within 

 and, though not so irregular in shape, are subsimilarly dentate 

 on the inner margin; although deficient in lateral thoracic spinules, 

 it appears to be an Aplagiognathus in the sense understood by 

 Bates. This interpretation of Aplagiognathus, however, leaves 

 Mallodon melanopus and allied species unassigned generically, 

 for they have a very convex form of body, hind parts of the pro- 

 thorax as in Mallodon and strongly deflexed small nude mandi- 

 bles, altogether similar in the sexes and not at all like those figured 

 by Bates as pertaining to Aplagiognathus hybostoma and still less 

 those of guatemalensis. These species are certainly not Mallodon, 

 being very different in structure and appearance; neither do they 

 seem at all appropriately placed with Aplagiognathus spinosus, hybo- 



