Royal Physical Society. 221 



thickened, and the tarsi, and more especially the last joint 

 and claws, greatly developed. The anterior tibiae have three 

 teeth ; the middle and posterior thighs and tibiae are robust, 

 but the tarsi are long and slender. The outer claw of the 

 anterior tarsi is much larger than the inner. The middle and 

 posterior claws are simple, and of equal proportions. 



Although this species is very closely allied to the preceding, — 

 so much so as to suggest the idea of its being its male, — I find 

 so many points of difference which I cannot consider sexual, 

 that I am satisfied it belongs to a distinct species. Putting 

 aside the difference in colour, which may be ascribed to the 

 score of variation, the much more developed mandibles, and 

 the immensely thickened legs and anterior tarsi, and the 

 smaller pygidium, which may be viewed as sexual (although 

 in no other species of the group are sexual differences deve- 

 loped to such an extent), we have very marked differences in 

 the proportions and form of the head, thorax, and elytra ; 

 the head is proportionally broader and more projecting in 

 front, and the inequalities on the surface are fewer and less 

 marked than in Jamesoni ; the thorax and elytra are more 

 shining and smooth in the latter, the punctures deeper and 

 better defined. The thorax is of a different form ; in Jamesoni 

 it is not nearly so convex, the curve proceeding gently and 

 gradually from the base without any rapid or abrupt rise ; 

 while in Crassimanus it takes a very marked rise, both in 

 front and behind ; in the latter also it is broader than the 

 elytra ; in the former considerably narrower. The former has 

 the anterior angles only slightly produced ; the latter has 

 them much more projecting. The reflexed margins are greatly 

 more marked in Crassimanus, which also has the margin all 

 the way round ; while in Jamesoni it disappears on the base. 

 The scutellum is smooth and nearly impunctate in the one ; 

 in the other it is strigosely granular. The elytra in Crassi- 

 manus are proportionally longer and narrower, and are 

 nearly parallel, very slightly, if at all, dilated behind: while in 

 Jamesoni the dilatation is well marked. In it the pygidium 

 is smooth and shining ; while in this species it is dull, and 

 has a number of longitudinal grooves or striae. These differ- 

 ences satisfy me that the two species are distinct. 



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