SPHENISCOSOMUS. 449 



The insect is of a castaneous or obscure rufous colour. The antenna? are ciliate on 

 their inner edge and half the length of the body in the male, much shorter in the 

 female ; the second and third joints are small. The thorax is very coarsely, thickly 

 punctate, with the hind angles sharply and obliquely unicarinate, and the basal sulci 

 long and rather shallow. The elytra are narrowed from the base in the male, more 

 parallel in the female ; seriate-punctate, the punctures placed in almost obsolete striae ; 

 the interstices are almost flat, each with an irregular double row of widely scattered 

 fine punctures. 



2. Spheniscosomus lanuginosus. 



cJ . Very elongate, flattened above, shining, rufo-castaneous, somewhat thickly clothed with long, decumbent, 

 rather coarse, cinereous hairs. Head very coarsely, closely umbilicate-punctate ; antennae extending to 

 a little beyond the hind angles of the prothorax, joint 3 short, slightly longer than 2. Prothorax broader 

 than long, rapidly narrowing from the base, the sides very feebly sinuate behind ; the hind angles diver- 

 gent, slightly incurved at the tip, sharply unicarinate ; the basal sulci short ; the surface exceedingly 

 coarsely, deeply, closely punctate, the punctuation becoming more crowded near the anterior angles and 

 very coarse on the basal declivity, the disc with a smooth depressed space along the middle behind. 

 Elytra three and two-thirds longer than the prothorax, gradually narrowing from the base, flattened on 

 the disc ; finely seriate-punctate, the punctures somewhat widely separated, the striae obsolete, except on 

 the basal declivity and along the suture ; the interstices almost flat, each with two rows of fine punctures. 

 Beneath rather sparsely punctate, the punctures fine on the abdomen, coarser on the metasternum, and 

 very coarse and umbilicate on the prosternum and propleurae. 



Length 15, breadth nearly 4 millim. 



Bab. Mexico, Omilteme in Guerrero 8000 feet (H. H. Smith). 



One specimen. This species resembles Melanotus prolixus, but differs from it in 

 having the sides of the mesosternal cavity raised ; the punctuation of the thorax is 

 extremely coarse, even on the basal declivity (instead of finer on this part, as in 

 M. prolixus). The antennas are rather short, and not ciliate on their inner edge. 



3. SpheniscOSOmuS tropicalis. (Tab. XX. figg. 7, 8\ 7 a, fifth ventral 



segment.) 



Elongate, flattened above, shining ; castaneous or rufo-castaneous, the elytra with the apex narrowly, and 

 sometimes the suture and lateral margins towards the tip, infuscate or black, the head, or the head and 

 prothorax (except in the middle behind), also sometimes infuscate or black ; beneath usually darker 

 than above, the propleurae, sides, and last two ventral segments of the abdomen sometimes black ; 

 above and beneath very sparsely clothed with rather coarse, decumbent, long, cinereous or yellowish- 

 cinereous hairs. Head very sparsely, coarsely punctate, the frontal carina rounded ; antennae about two- 

 fifths of the length of the body in the male, much shorter in the female, ciliate on the inner edge in the 

 male the third joint intermediate in length between the secoud and fourth. Prothorax broader than 

 long, narrowing from the base and with the sides somewhat abruptly converging in front in the male, more 

 parallel behind in the female ; the hind angles moderately long, divergent, slightly incurved at the tip, 

 bicarinate the outer carina sharply defined, the inner one feeble and sometimes obsolete, especially in the 

 females ; the basal sulci moderately long, deep ; the surface with very widely scattered fine or moderately 

 coarse punctures, which become coarser and more crowded towards the anterior angles, deeply canaliculate 

 behind and with a space along the middle of the basal half impunctate. Elytra more than three times 

 the length of the prothorax, narrowing from the base in both sexes ; seriate-punctate, the punctures 



biol. centr.-amee., Coleopt., Vol. III. Pt. 1, January 1896. 3 IE 



