476 Mr. H. W. Bates on the Longicorn Colcoptcra 



and densely fringed. The prostcrnum is simply rounded, the 

 mesostcrnum steeply inclined in front and bituberculatcd. The 

 terminal joints of the male antenna; arc moderately slender and 

 ciliated beneath. 



This is a common species throughout the Amazon region, on 

 felled trees in the forest ; it is also common, apparently, in 

 French Guiana. I have seen it in collections under the name of 

 A. lateralis, Dej., which appellation I have adopted. A. Jaspi- 

 deus, Germar (Sp. Nov. p. 475), and A. consentaneus, Dej., ac- 

 cording to specimens sent to me by M. Deyrollc of Paris, are 

 closely allied to A. lateralis; but their pro- and mesosterna arc 

 strongly convex. Our species is also near A. satellinus, Erichs. 

 (Consp. Insect. Peru., p. 143) ; but the latter is described as 

 having the apex of the elytra armed with a very short spine. 



19. Acanthodcres bivitta, White. 



Sleirastoma bivitta, White, Cat. Long. Col. in Brit. Mns. ii. p. 354. 



This species was placed by Mr. White, whose description 

 otherwise is a very good one, in the genus Steirastoma. It 

 differs from that group in having simple instead of complex 

 lateral thoracic tubercles. It stands in certain French collec- 

 tions as A. tardigradus of Dejcan's Catalogue. It is a common 

 insect, in the Upper Amazons, on the trunks of felled trees of a 

 certain species, to whose bark its colours are assimilated. It is 

 found also in French Guiana. It is inactive in its habits, but 

 appears to be extremely prolific. The opposing faces of the pro- 

 and mesosterna arc steeply inclined and bituberculatcd. 



§ 2. Antennae with the terminal joints thickened and ciliated in the males, 

 or triangularly dilated in both sexes ; the third or third and fourth 

 joints often furnished with tufts of hairs. (Pteridotelus, White, in 

 part.) 



[Although so diversified in structure and oraamentation of 

 antenna?, this group is homogeneous in the form of the body, 

 sterna, and in other respects.] 



20. Acanthodcres spectabilis, n. sp. 



A. elongatus, subdepressus, postice attenuatus, niger, velutinus, ma- 

 culis niagnis albis ornatus : antennarum articulo tertio scopa 

 magna nigra instructo. Long. 8 lin. <$ $ . 



Head black, with a triangular white spot in the middle of the 

 forehead, two between the antenna? of the same colour, and two 

 rounded on the vertex. Antenna? black, base of the fourth and 

 following joints grey, the third joint encircled by a thick brush 

 of black silky hairs, which extends nearer to the base on one 



