36 On new Genera and Species of Coleoptera. 



No other described species is allied to this in colour. My 

 specimens are from Ega, and, like others from the Amazons 

 district, were collected by Mr. Bates, F.R.S. 



Prostenus iocerus. 



P. supra viridcscenti-niger, infra pedibusqne chalybeatis ; antennis 

 violaceis ; prothorace transverse. Long. 5| lin. 



Hah. Pard. 



Above greenish or bluish black, beneath and legs steel- 

 blue, antenna? violet ; head rather sparingly punctured ; pro- 

 thorax transverse, well rounded at the sides, closely and 

 minutely punctured ; scutellum triangvdar ; elytra finely seriate- 

 punctate, not striated ; antennae with the eighth, ninth, and 

 tenth joints broadest. 



The prothorax is transverse as in the preceding and in P. 

 jjeriscelisj Perty, but differs from both in coloration, and 

 structurally from the latter in the less dilated antenna3. 



Prostenus jparilis. 



P. supra cyaneo-niger, infra pedibusque chalybeatis ; antennis vio- 

 laceis ; prothorace angustioro, i>aulo longiore quam latiore. Long. 

 51 lin. 



Rah. Amazons. 



Above dark bluish black, beneath and legs steel-blue ; an- 

 tennas violet ; head closely punctured ; prothorax rather longer 

 than broad, slightly incurved at the sides near the base, minutely 

 and very closely punctured ; scutellum scutiform ; elytra finely 

 seriate-punctate ; antenna; with the eighth, ninth, and tenth 

 joints broadest, the seventh slightly dilated ; intermediate 

 and posterior femora strongly clavate. 



Allied to the preceding, but prothorax oblong, not trans- 

 verse, and the intermediate and posterior femora strongly 

 clavate. 



Prostenus nitens. 



P. augustior, nitide fuscus ; clytris nitidissime cupreo-fuscis ; an- 

 tennis violaceis. Long. 4| lin. 



Hah. Amazons (Ega). 



Narrower, glossy brown, except the antennas and elytra ; 

 the former violet, as long as the body, all the joints from the 

 second flattened and gradually dilated to the ninth and tenth ; 

 prothorax narrow, longer than broad; elytra very glossy 

 copper-brown, depressed on the basal half and towards the 

 suture concave, finely seriate-punctate ; femora moderately 

 clavate ; tarsi elongate, slender. 



A very distinct species. 



