394 Mr. G. J. Arrow on Rutelid Coleoptera. 



same position. These two species are otherwise scarcely 

 distinguishable. 



Tiie East-African A. punctipenmsj Fahr., another species 

 of almost identical appearance, may be distinguished from 

 those just referred to by the entire absence in both sexes of 

 any armature of this kind. In a former paper dealing with 

 Rutelid Coleojitera from the Transvaal (Ann. & Mag. Nat. 

 Hist. (7) iv. p. 120), regarding all tlie unarmed specimens 

 as females, I failed to distinguish these two species, and 

 referred a specimen of A. puncti'pennis to the West- African 

 species. Tiie range of these insects is tlierefore still less 

 wide than 1 there stated. A. punctipennis, Fahr., though 

 distinct from A. hirtellus, Lap. { = cine)'arius, Burm.), is, I 

 believe, identical with A. cephalotes^ Gerst. 



In all these forms the two sexes are closely similar and the 

 appearance of both that of typical Adoreti; but there are 

 members of the group in which tlie male characters are 

 greatly exaggerated, the liind legs being of enormous size 

 and the characteristic appearance of the true Adoretus almost 

 lost. One of these is A. olbosetosus, Waterh. (which has been 

 twice redescribed by M. Fairmaire under the names of afbo- 

 hispidus and hystrix). For this a new genus will have ulti- 

 mately to be formed, but I do not propose to do this at present, 

 as I have not yet been able to see the female, which appears 

 to be much rarer than the male. 



An East-African insect not very distantly related to the 

 last has been described by Herr Brenske under the name of 

 Trigonochilus coriaceus. The author was evidently not 

 acquainted with the nearest allies of this remarkable beetle, 

 lor he has formed a new subfamily for it. Had the female 

 only been known, however, tlie species would no doubt have 

 been placed in tiie genus Adoretus, the peculiarities which 

 have induced its separation virtually all resulting from the 

 great developments peculiar to the male. Here again there 

 is a strong spine upon the lower edge of the hind femur, 

 which, with the tibia, is greatly enlarged, as in A. albosetosua. 



In the British Museum is an undescribed species from 

 Angola, which, although differing considerably in general 

 appearance from T. coriaceus, may well be placed in the same 

 genus. The two sexes of this show similar remarkable 

 differences. 



Trigonochilus politus, sp. n. 



Breviter ovatus, nitidus, rufo-testaceus ; capite rugoso-punctato ; 

 prothorace parvo, lateiibus valde arcuatis, longe flavo-hirtis, 

 marginibus reflexis, angulis posticis rotundatis, disco fere polito ; 



