Mr. C. J. Gahan on new Longicorn Coleoptera, 461 



what bitid, the two posterior more acute ; with, in addition, a 

 feeble median cariniform elevation placed just before the 

 posterior transverse depression. Elytra exhibiting delicate, 

 silvery-grej, irregular fascige, which change their position 

 according to the light in which they are viewed. The 

 granules with which the elytra are furnished are wide apart, 

 arranged in three rows on the disk of each and more irregu- 

 larly on the sides. The second ventral and the terminal 

 dorsal segment of the abdomen fringed with tawny-red hairs. 



Arrhythmus punctatuSj sp. n. 



Fuscus : capita supra prothoraceque sat sparsim punctatis et sub- 

 tiliter griseo-pubescentibus : disco prothoracis pauUo ante medium 

 acute bituberculato ; elytris nitidis, flavescentibus, sat sparsim 

 fortiterque punctatis, punctis, plagis duabus basalibus, macubs 

 duabus parvis ad medium et apice fuscis ; pedibus flavis, clavis 

 femorura fuscis ; antennis corporo duplo fere aequaUbus, flavis, 

 articubs primo et secundo cum apicibus ceterorum infuscatis. cS . 



Long. 10-20 mm. 



Hah. Imerina Mountains. 



Prothorax gradually and slightly narrowed from the base 

 to the apex, with two distinct and rather sharp tubercles on 

 the anterior part of the disk. Elytra strongly and somewhat 

 sparsely punctured, yellowish, with a plaga on each side at 

 the base, a small spot on each at the middle, the apex, and all 

 the punctures dark brown ; the elytra are scarcely constricted 

 before the apex, the latter tiierefore does not appear to be 

 expanded ; the apices of each are subacuminately rounded 

 and produced near the suture into a short blunt spine. The 

 body underneath is covered with a greyish pubescence ; the 

 underside of the prothorax is somewhat transversely rugose, 

 and the sides of the metasternura are sparsely and strongly 

 punctured. The antennae are about twice as long as the 

 body, yellowish, with the first two joints and the apices of 

 the others brownish ; the scape is rather narrow at the base, 

 gradually thickened up to the apex, and rather thickly but 

 not rugosely punctured. 



From A. rugosipennisj Waterh., and A. paUimembris, 

 Fairm., this species may be distinguished easily by the sliape 

 of the prothorax and by the nature of the punctuation, as 

 well as by other minor characters. Of the two specimens 

 that 1 have seen one is very much larger than the other. It 

 is probable that varieties may occur in which the dark brown 

 of the elytra occupies a much larger extent. 



