756 Coleopterological Notices, VI. 



shining integuments, black color, rather more convex eyes and 

 other characters. 



jVOTOXUS Fabr. 



This genus contains numerous species in North America, but 

 is more abundant in the temperate than in the tropical regions of 

 the continent. The thirty-two species included in the table be- 

 low, appear to be rigorously definable and without suspicion of 

 intergradation, as far as can be observed with the abundant ma- 

 terial before me. The species in fact seem to be unusually con- 

 stant through long series, in the majority of cases even in colora- 

 tion, and types of coloration have proved so stable that it is 

 found convenient to divide the genus into groups based primarily 

 upon these characters. It seems evident, moreover, that this may 

 be as natural a grouping as any which can be provisionally 

 assumed. 



The thoracic horn is another character heretofore regarded as 

 especially prone to variation, which I have found to be quite con- 

 stant in general form and structure within the same sex of the 

 various species, and this is what might be anticipated from analogy. 

 It is true that the horn is an unusual and greatl}' developed struc- 

 ture of scarcely obvious utility in the economy of the animal, 

 if we consider the genus in relation to the other genera of An- 

 thicini; but, on the other hand, we must remember that within the 

 large genus Notoxus, the horn, whatever its use, whether a pro- 

 tection for the head or something more obscure, is a remarkably 

 characteristic generic feature, and consequentl}' a long established 

 and permanent structure, and ought not to possess much specific 

 variability at the present time. 



The species may be readily recognized as follows : — 



Elytra entirely black, sometimes feebly and indefinitely paler toward the 



apex 2 



Elytra black, each with two large oblique spots of pale tint 3 



Elytra black, crossed by two pale fascia; - 4 



Elytra more or less pale, with a single dark fascia behind the middle, which 

 is generally produced anteriorly along the suture to a greater or less de- 

 gree, frequently also with dark markings anterior to the fascia 5 



Elytra pale, with a dark fascia at the middle, and another which is either 



apical or subapical 15 



2 — Elytral vestiture uniform in color; eyes larger and more prominent. 



1)icolor Say 



