40S Mr. C. J. Gahan on ne.i 



Cantharoctenus somalius, sp. n. 



cT . Rufo-piceus ; mandibiilis falcatis, apice obliquiter truncatis et 

 bidentatis ; capite fronte dense punctato, supra sparsius rainii- 

 tiusque punctato ; prothoraee disco nitido baud dense punctato, 

 versus latera crebre fortiterque punctato ; elytris dense punctatis ; 

 antennis 19-articulatis, articulis 3°-18™ infra ad apicem processu 

 lamelliformi vix emarginato instructis, articulis 4''-18"' infra ad 

 basin bidentatis. 

 Long. 23-24, lat. 9 mm. 



Hab. Somali. 



Tliis species so closely resembles G. Barchelll, Westw., 

 that I was at first sight inclined to consider it the same. It 

 differs, however, in two important characters. The antenn;e 

 are 19-jointed, and not l8-jointed, as described by Westwood 

 for the male of C. BurchetU. The lamelliforra process with 

 which each of the joints from the third to the eighteenth is 

 provided on the underside at the distal extremity is only very 

 slightly emarginate at its lower free border (the emargination 

 on some of these processes is, in fact, scarcely observable) . 

 The corresponding processes in G. Burchelli are rather deeply 

 incised, while in G. insignis, Gerst., the incision is carried 

 down to the base. In the latter species the antenna are 

 described as having twenty joints, I question whether 

 Gerstaecker was right in regarding his type as a male, inas- 

 much as the mandibles are of a different form to those of the 

 males of G. Burchelli and of the species now described, and 

 quite resemble the mandibles of a female G. Burchelli from 

 l)amaraland, in the British Museum collection. At the same 

 time it is quite possible that the males of this, as of other 

 Prionid genera (e. g. Gacosceles and Priotyrannus), may exhibic 

 dimorphism in the structure of the mandibles. 



The chief differences between the three species of Gantharo- 

 ctenus may be briefly recapitulated as follows: — 



Autennte 20-jointed. Distal process of antennal 



joints very deeply divided C. insigyiis, Gerst. 



Endara. 

 Antennfe 18-jointed. Distal process of antennal 



joints deeply incised C Burchelli, Westw. 



Damaraland. 

 Antennae 19-jointed. Distal process of antennal 



joints feebly emarginate C somalms, Gahan. 



Somali. 



T'aurotagus Greenfieldi, sp. n. 

 Eufo-piceus, pubc griseo-sericea sat dense obtectus ; prothoraee 



