230 MEMOIRS ON THE COLEOPTERA 



be very constant in color; others, such as trinitatis, are dimorphic 

 in that respect, while some at least, such as versicolor, are very con- 

 fusingly inconstant, not only in coloration but in size and somewhat 

 in outline. Pinguis probably belongs to the same section as versi- 

 color, but differs apparently in the denser thoracic punctures, as 

 well as the shorter and broader elytra, those of versicolor being 

 scarcely at all suggestive of bivittata. Atra and morata constitute a 

 rather well denned subgeneric group. Mollipilosa, lugens and pin- 

 guis are defined above from the original diagnoses. 



Leptacmaeops n. gen. 



This genus differs from the preceding very much in general 

 habitus, due to the elongate form of the body and the long filiform 

 antennae. We have two subgeneric groups as follows: 



Prothorax always distinctly constricted at apex; size moderate, the 

 anterior parts never, the elytra frequently, paler in color. .Group I 



Prothorax not constricted at apex and pale in color, the elytra always 

 black; size much smaller Group II 



These groups are very unequal in extent, the second comprising 

 but a single species at present. 



Group I. 



Subgenus Leptacmaeops in sp. 



Under this title are to be included a large number of species and 

 subspecies, frequently rather closely allied among themselves and 

 sometimes exhibiting a chromatic dimorphism, similar to that noted 

 in trinitatis of the preceding genus; they are definable in a fairly 

 satisfactory manner as follows : 



Elytra distinctly modified at base by an abrupt coarseness or marked 



sparsity of the punctures, this area in the black forms usually bright 



red 2 



Elytra not modified in basal sculpture 10 



2 Prothorax very short before the ante-medial lateral prominences, 



which are feeble and rounded as usual 3 



Prothorax notably produced at apex, the constriction less abruptly 



formed, with its bottom broadly rounded in concavity 8 



3 Elytra always notably more than twice as long as wide; fifth antennal 



joint very much longer than the first 4 



Elytra barely more than twice as long as wide; antennae shorter though 



similarly slender, the fifth joint not distinctly longer than the first; 



size very much smaller 9 



