Mr. F. P. Pascoe on the Brenthidoe. 391 



Iihystenus frontalis. 

 I. nigro-fuscus ; capitis fronte canaliculata ; rostro basi profunde canali- 

 culate* ; elytris late bivittatis, spina exteriore cylindrica, apicem versus 

 acuta. 

 Hab. Aru. 



Very like the last, but less elongate. The narrow groove extending 

 the whole length of the head and running into the broad canal at 

 the base of the rostrum, where it gradually spreads out and is 

 obliterated at about a quarter of its length, affords good diagnostic 

 characters when compared with the same parts in /. Wallacei, where 

 the head is entire, and the rostral canal is uniformly narrow, and 

 continued as far as the insertion of the antenna?. The apical spine 

 in this species is cylindrical, except at the tip, where it suddenly 

 becomes conic and pointed. 



Ithystenus fumosus. 

 I. nigro-fuscus ; capitis fronte late canaliculata, transversim corrugata ; 



elytris concoloribus, spina exteriore filiformi, elongata. 

 Hub. Batcliian. 



In some individuals of this species the posterior margin of the 

 prothorax is of a deep blood-red, or the bases of the femora are 

 nearly of the same colour ; but it is well distinguished by having on 

 each side of its frontal canal a finely sculptured series of transverse 

 hair-like plaits. The elytra are entirely dark brown, and the apical 

 spine is unusually long for this genus, its length being about twice 

 the breadth of the elytra. 



Iihystenus linearis, 

 I. nigro-fuscus ; capitis fronte tenuiter canaliculata ; elytris basi rubro 



maculatis, spina exteriore brevi, subconica. 

 Hab. Batchian. 



The short, conic, apical spine and the clear blood-red spot at the 

 base of each elytron, almost confined, however, to the base of the 

 third of the raised lines, where it seems to replace the longer yellow 

 line of /. angustatus, &c, will readily distinguish this species from 

 any here destribed. 



Ithystenus opliiopsis. 

 I. nigro-fuscus ; prothorace antice curvato ; elytrorum spina exteriore 



brevi, incrassata, compressa. 

 Hab. New Guinea (Dorey). 



The curved prothorax, presenting a sort of gibbosity above, and 

 the short, stout, deeply compressed spine of the elytra, are characters 



vol. i. 2 F 



