756 Coleopterological No(icei<, VI. 



shining integuments, black color, ratlior more convex eyes and 

 other characters. 



XOTOXirS Fabr. 



This genus contains luimerons species in North America, but 

 is more abundant in the temperate than in the troi)ical 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 Avith 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 primarih^ 

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

 be as natural a grouping as ^ny which can be provisionally 

 assumed. 



The thoracic hoiii 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 analog^'. 

 It is true that the horn is an unusual and greatly 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, wiiatever its use, whether a \)vo- 

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

 characteristic generic feature, and consequentl3^ a long established 

 and permanent structure, and ought not to possess much specific 

 variabilit}' 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, cacb witli two lai-jjce obli(|ue spots of pale tint 3 



Elytra black, crossed by two pale fascia; 4 



Elytra more or less i)alc, with a sinj^le dark fascia behind the middle, Avbich 

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

 gree, fre<iuently also with dark markings anterior to the fascia 5 



Elytra pale, with a dark fascia at the middle, and anotlier Avliich is either 



apical or subapical 15 



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



bicolor Say 



