210 Mr. D. Sharp's Cordributions to the 



yellow, very finely punctured. The legs are shorter, the 

 hind tarsi much shorter than in S. f/racilis. The male 

 has a deep, narrow notch in the 7th segment of the hind 

 body beneath, and the Gth segment has along the middle a 

 broad, longitudinal impression, the sides of which arc more 

 densely pubescent than the other part of the segment. 

 Tapajos ; one specimen. 



Cryptobium. 



This genus Is known to be much more richly repre- 

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

 liemisphere; about twenty-two sj^ecies have been hitherto 

 described from the southern half of America, and I here 

 add twenty species, — eighteen discovered by Mr. Bates and 

 two by Dr. Trail. These twenty s])ecies show a remark- 

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

 looking Cryptobhim f/if/as offers, indeed, a most striking 

 contrast in its a])i)carance to the completely cylindric 

 Crypiohium ci/lindricutn. One of the most interesting 

 ])eculiarities of the geiuis is, that in the males of some of 

 the species the ventral plate of the fourth segment of the 

 hind body is furnished with j^rojections or a])pendages of 

 size and Ibrm differing according to the species. 1 have 

 ascertained that in one of the species here described 

 ( Crypiohium alter nans) this lobe varies in its development 

 \\\ different males, in a manner similar to that which 

 occvirs in the male projections and processes found on the 

 more anterior parts of the body in various Coleoptera. 

 It apjiears probable to me that these developments in 

 Cryptobium are of a similar character and origin to those 

 secondary sexual characters considered by Darwin to play 

 an important part 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 Stapliylinidce on the more apical 

 segments appear to me undoubtedly to do. 



1. Cryptobium giyas, n. sp. Latum, nigrum, caplte 

 thoraceque opacis, parce obsolete punctatis ; elytris sub- 

 opacis, dense fortiterque punctatis. Long. corp. 7 lin. 



jNIas : abdomine segmento 7° ventrali medio profunda 

 excise, excisione ad apicem impressionis majoris locato. 



Fern. : abdomine segmento 7" ventrali apice medio leviter 

 cmaru'inato. 



