210 Mr. D. Sharp's Contributions to the 



ycllo-w, very finely piiiictnred. The legs are shorter, the 

 hind tarsi uuich shorter than in *S'. (jracilis. The male 

 has a deep, nari'ow notch in the 7th segment of the hind 

 body beneath, and the 6th segment has along the middle a 

 broad, longitudinal impression, the sides of whieh are more 

 densely pubescent than the other part of the segment. 

 Tapajos ; one specimen. 



CllYrTOBIUM. 



This genus is known to be much more richly repre- 

 sented in species in the New World than it is in the other 

 hemis])here; about twenty-two species have been hitherto 

 de>cril)ed from the southern half of America, and T here 

 add twenty species, — eighteen discovered Ijy ^Ir. IJates and 

 two by Dr. Trail. These twenty species sIioav a remark- 

 able diversity in form. The broad, flat, and ferocious- 

 looking Cri/ptohium r/ii/as offers, indeed, a most striking 

 contrast in its appearance to the completely cylinch-ic 

 Cryj)tohium cijlindricum. One of the most interesting 

 peculiarities of the genus is, that in the males of some of 

 the species the ventral ]ilate of the fourth segment of the 

 hind body is furnished with projections or appendages of 

 size and form diflering according to the species. 1 have 

 ascertained that in one of the species here described 

 (^Cri/])i<)hium aJternatis) this lobe varies in its development 

 in dillerent males, in a manner similar to that which 

 occiu's in the male projections and ])rocesses found on the 

 more anterior ])arts of the body in various Coleoptera. 

 It appears probable to me that these develoi)ments in 

 Cryyiohinm are of a similar character and origin to those 

 secondary sexual characters considered by Darwin to play 

 an important ])art as influencing sexual selection; and 

 that they exercise little or no influence on the direction of 

 the movements of the abdominal segments, as the notches 

 and processes so common in SStapiiylinidic on the more apical 

 segments appear to me undoubtedly to do. 



1. Cryptohium giyas, n. sp. Latum, nigrum, capite 

 thorace(pie opacis, })iirce obsolete punctatis ; elytris sub- 

 02:)acis, dense fortitenpic punctatis. Long. corp. 7 lin. 



INIas : abdomine segmento 7° vcntrali medio ])rofundc 

 cxciso, exeisione ad apieem impressionis mnjoris locato. 



Fem. : abdomine segmento 7" venlrali apice medio leviter 

 cmarginato. 



