Coleo'ptera from South Africa. 177 



retuse behind, the supra-lateral part carinate, the cariua serrulate, 

 the disk with a sharp, median smooth ridge on each side, ending 

 suddenly at the top of the posterior declivity, the interval between 

 the suture and the dorsal ridge smooth, the other interval with an 

 indistinct series of very small tubercles. Length 15, width 9 mm. 



Hah. Mozambique (Rikatla). 



Easily distiBguished from all the other described 

 South African species of Micrantereus by the smooth 

 dorsal ridge ending abruptly at the top of the posterior 

 declivity in an acute point, in exactly the same manner 

 as in Amiantus carinatus, of the group Molurides. In the 

 male the posterior declivity is not so abrupt as in the 

 female, and the apical part of the dorsal ridge is, there- 

 fore, not so marked ; the tubercles in the interval 

 between the median ridge and the supra- lateral part are 

 more seriate ; and the intermediate and posterior tibige 

 are as much incurved as they are in M. gratiosns, of 

 which the present insect may prove to be a variety. 



AcASTUS, n. gen. 



Mentum as in Hoplonijx, Thorns., last joint of maxillary palpi 

 secui'iform, labrum transverse, truncate in front, eyes large, 

 divided on the vertex by a mere line, supra-antenual crests 

 produced in a coalescing semicircular ridge overhanging the anterior 

 part of the head ; antennae not reaching the median part of the 

 elytra, massive, the joints sub-moniliform, the median ones slightly 

 dilated inwardly and somewhat serrate, the apical ones sometimes 

 more or less pyrif orm ; prothorax plane, as broad as long, a little 

 rounded in front laterally, but wdth the posterior angles very 

 sharp, carinate laterally ; elytra sub-oblong, parallel, broader 

 than the prothorax, not very convex ; legs moderately long, 

 anterior tibiae deeply sinuate at the base, anterior femora wnth a 

 broad conical tooth near the apical part. 



Distinguished from Ho2:)lonyx by the shape of the 

 antennae, the joints of which are shorter, much more 

 massive, the third not longer than the first ; the supra- 

 antennal crests are much developed and coalesce in the 

 middle. 



TRANS. ENT. SOC. LOND. 1896. PAUT II. (jUNE.) 12 



