2;";0 ;Mr. D. Sharp's Cuntributions to the 



beai'ine: an extraordinary resemblance to one another in 

 appearance and general characters, but distniguished 

 nevertheless by striking and highly important ])rimary 

 and secondary sexnal characters. In the case of some 

 of these species {L. jjuiicticcps and L. decisum, for in- 

 stance), after a very carefiil examination, I am nnable to 

 see any satisfactory distinctive charactei's except the sexual 

 ones; and an examination of the male intromittcnt organ 

 has convinced me that it is extremely doubtful -whether 

 fertilization could be effected by the sexes of different 

 species, even if attempted. By this I mean that if, for 

 cxami)le, the male and female organs in L. opalescens be 

 mutually adapted for the facilitation of fecundation, as it 

 is only reasonable to suppose is the case, then from the 

 great difference we find to exist in the intromittcnt organs 

 of the males of the exactly similar L. pitncticeps, Ave are 

 fairly entitled to conclude that fecundation of the female 

 of L. opalescens by it would be dillicult. It may, perhaps, 

 not be out of place to state here my conviction that these 

 modifications of sexual characters will be found to be very 

 directly in relation with those " laws of variation," a 

 knowlcdcre of which is so much to be desired for tlie 

 further elucidation of the question of the differentiation 

 of species. 



1. Lathrohium macroccpludum, n. sp. Kobustum, 

 nigrum, nitidum, elytris abdomincque nigro-piceis, pcdi- 

 bus piceis ; ca])ite magno, crebrc fbrtiter punctato ; 

 prothoracc clytrisque parcius punctatis, illo tenuiter 

 canaliculato. Long. corp. 6^ lin. ; lat. (capitis) 1.', lin. 



i\Ias: al)domine segmcnto 7" ventrali a]iice profundc 

 triangulariter cxciso ; segmcnto 6" late triangulariter im- 

 presso, apice emarginato. 



The massive head of this species distinguishes it from 

 all others of the genus. The antennjc are stout, shorter 

 than head and thorax, slightly more slender at the ex- 

 tremity than the base; 1st joint about as long as the tlu'ce 

 following together, 3rd longer tliau 2iid, 4 — 10 differing 

 little from one another in length ; 11th joint slender and 

 pointed, longer than the lOtii, rusty at the extremity. 

 The liead is ratlicr broader than the thorax; it is a little 

 naiTowcd towards the front, is coarsely and rather closely 

 punctured; the punctuation rugose l)ehind the eyes, a 

 narrow space along the middle, smooth. Thorax fully 



