Dec, -1912.] Fall: North American Collops. 253 



Group B. 



Because of its close relation to tricolor, sublimbatus has been 

 tabulated in the preceding section, but the more or less pale elytral 

 margins would point to a position in the present group. If placed 

 here it would fall with conflncns, which differs by its entirely pale 

 margins, coarser punctuation and elongate basal antennal joint of 

 the d*. 



MargincUus occasionally occurs with head, under surface and 

 legs entirely pale, in which case it may be distinguished from georgi- 

 anus by the polished thorax and entirely pale margins of the elytra. 



Viftatus and marginellus occasionally have the thorax immacu- 

 late ; they are then separable from laticoUis and granellus by the 

 absence of elytral tubercles, and from confluens by the broadly tri- 

 angular basal antennal joint in the 6, and less coarsely punctate 

 elytra. 



Tibialis of the next group having the elytral spots confluent will 

 also fall with laticoUis, etc., but may be separated by the trilobed 

 yellow margin of the front and nontuberculate elytra. 



Both histrio and vcrsatilis of group C occur also with the elytral 

 spots confluent, but the sinuate basal antennal joint in the ^ will dis- 

 tinguish them from any species of the present group. 



Prothorax polished and strongly shining, at least medially (except in georgianus). 



Antennae of ^ very strongly acutely serrate, elytral vittae broad and scarcely 



narrowed at anterior third ; head pale in front of a line tangent to the 



anterior margins of the eyes; legs, except hind femora, pale. . . .liinbeHus. 



Antennae of (^ moderately serrate. 



Head in great part rufous, the sides only blackish, entire under surface 



and legs pale georgianus. 



Head mostly black, under side and legs more or less black (except in 

 some specimens of marginellus) . 

 Erect hairs entirely whitish, pale margins of elytra of nearly uni- 

 form width flaz'icinctns. 



Erect hairs of body black. 



Prothorax entirely rufovis. 



Elytra with minute tuberculiform elevations, size moder- 

 ately large. 

 Pale sutural and lateral margins of the elytra con- 

 tinuous around the apex laticoUis. 



Pale margins of the elytra not continuous around the 

 apex granellus. 



