136 Memoirs on the Coleoptera 



des Loges; at any rate, I can find no reference to it; Cylindrocerus 

 cyanens seems to resemble it, but, according to Boheman's descrip- 

 tion, it differs in its longer beak and in the uni- and not bidentate 

 anterior femora ; the metasternum is coarsely and sparsely punctate, 

 but a large medial part is flat, finely and very densely punctate, 

 squamulose and with a deep medial stria; the first two ventral 

 segments are feebly concave medially and finely, very densely 

 punctate and similarly clothed. There are doubtless a considerable 

 number of species in the genus. 



Diastethus Pasc. 



Although allied to Gladosius and Stegotes, the species of this 

 genus are immediately distinguishable by the prominent mesoster- 

 num, fiat prosternum and the sharply circumscribed areas of dense 

 scales on the under surface, which features are not possessed, in 

 even rudimentary degree, by either of the genera mentioned. 

 From Gladosius the species differ also in having a normally small 

 antennal club, although most of them are similarly metallic in 

 body coloration; this last character is wholly unknown in Stegotes. 

 In the treatment of the Central American forms, Mr. Champion 

 combined several distinctly characterized genera, and, of the species 

 there described, only eurhinoides and violaceus can properly be 

 considered under the genus Diastethus; superbus and sulcipennis, 

 obliquus and rufipennis undoubtedly represent at least three distinct 

 genera, and humerosus and humeronotatus belong without much 

 doubt to the genus Micro stegotes, defined further on in the present 

 paper, although no mention is made of the mandibles, which are 

 so peculiar and characteristic in Microstegotes; most of the other 

 species there described belong to the genus Stegotes. There are in 

 my collection at present seven species of Diastethus as follows : 



Body metallic in coloration 2 



Body deep black throughout; mesosternum horizontally much produced, deeply 



sinuate at apex • • 5 



2 — Body shorter, broadly rhomboidal and bright cupreous, the legs blue-greenish. 

 Beak slender, evenly arcuate and as long as the elytra, minutely, sparsely 

 punctate and cylindric, a little more strongly punctate basally; antennae 

 slender, evidently behind the middle, the first funicular joint not quite as 

 long as the next two, the second between two and three times as long as 

 wide, the club solid, with indistinct sutures, subglobular and as long as the 

 preceding three joints; prothorax very short and transverse, fully three- 

 fourths wider than long, in lateral profile most convex near the base; sides 

 subparallel in less than basal half, rapidly rounding and thence very oblique 

 and feebly arcuate to the strong tubulation; surface distinctly but remotely 

 punctate, the punctures coarser medio-basally; basal lobe very broadly 

 rounded, with upturned edge, the lateral impressions moderate; scutellum 

 large, strongly transverse, flat, the hind margin finely and strongly cuspid; 

 elytra slightly elongate, twice as long as the prothorax and a third wider, 



