128 Mr. D. Sharp on some 



1849, and the preparation of this paper is not such as 

 to enable it to be utilized for the purposes to Avhich I am 

 now alluding. 



I hope the remarks I have above made on the defi- 

 ciencies of our knoAvledge of the entomology of these parts 

 of the world may fall in the way of some persons who will 

 try to diminish our ignorance. 



I hope, too, that Mr. Blackburn himself, whose skill and 

 experience render his residence in these islands of very 

 special value, may be able to continue his reseai'ches in 

 Oahu, and, if possible, extend them to the other islands of 

 the group. 



The material he has at present transmitted me has not 

 been sufficiently amj^le to enable me to decide, in certain 

 difficult cases, as to the sexual characters of some of the 

 species, and until this is done, the specific distinctions 

 themselves are involved in some doubt. It is stated by 

 all the authors, who have lately treated on the Nitidididce, 

 that the small supplementary segment at the extremity 

 of the hind body, which exists in some individuals and 

 is absent in others of the same species, is characteristic of 

 the male. I find, however, that this is often incorrect, 

 and, in some cases, it is the females that are thus con- 

 structed. In Bracliyj)terus vestitus, Kies., and B. gravi- 

 dus, Murray, it is certainly the females which bear the 

 additional segment, and yet, in the closely-allied Amartus 

 rufipes, Lee, a similar structure is (as coi'rectly stated by 

 Leconte) characteristic of the male. In the genus Cono- 

 telus, when an additional segment is extruded, it is 

 more usually in the female ; but this is not invariably 

 the case, for in some individuals of the other sex, the 

 usually internal terminal segment may have its apex pro- 

 truded, while, on the other hand, in the female this 

 segment is occasionally much retracted ; in the case of 

 Conotelus, therefore, recourse must be had to the form of 

 the dorsal and ventral plates of the last truly external 

 segment, if the sexes are to be correctly discriminated 

 without an examination of the internal organs. These 

 facts have made me hesitate before forming an opinion 

 as to the sex of the few specimens I have seen of the 

 species of the Brachypeplus imjjressus group. 



GONIORYCTUS. 



This is a new generic name proposed by Mr. Black- 

 burn, and adopted by me for three species which are very 



