Oct.,1917 Bulletin of the Brooklyn Entomological Society 83 



STUDIES IN THE HYDNOCERINI (COL.). THE 

 HYDNOCEROID GENERA. 



By Edward A. Chapin, M.S. 



After a careful study of a large collection of the. insects here- 

 tofore included under the genus Hydnocera Newman, it has 

 become evident that certain of the species differ from H. palli- 

 pennis Say, that species being the type of Hydnocera, to an 

 extent which warrants the erection of genera to include them. 

 In the characterization of the genus by Lacordaire (Gen. Col., 

 IV, 471) the ungues are stated to be " appendiculate, their basal 

 portion tooth-like." 



In Hydnocera pedalis Leconte and its related species, sobrina 

 Fall and parviceps Schaeffer, and in the group of species allied to 

 curtipennis Newman {longicollis Ziegl.), the ungues are simple, 

 but slightly thickened at the base. In these groups, however, the 

 structure of the antennae differs widely and considering the 

 uniformity of structure as seen throughout the two large groups,, 

 the pallipennis and the curtipennis groups, a second division is 

 made on the antennal characters. 



The genera may be distinguished from one another by the 

 following table : 



Ungues with a broad basal tooth Hydnocera Newman. 



Ungues simple, at most slightly thickened. 



Third segment of antennae about twice as long as broad, cylindrical ; 



prothorax much longer than broad Isohydnocera gen. nov. 



Third segment of antennae as broad or broader than long; trapezoidal; 

 prothorax subequilateral Wolcottia gen. nov. 



Isohydnocera gen. nov. — Body very elongate ; head short, vertical ; eyes 

 prominent, finely granulate, entire or minutely emarginate near antennal 

 insertion ; terminal segment of maxillary palpi cylindro-conical, that of 

 labial palpi large, triangular ; mandibles with a tooth near apex on the 

 inside. Antennae 11 -segmented, first segment thick, moderately long and 

 somewhat arcuate, second short, globose, third to ninth cylindrical, longer 

 than broad, tenth very large, forming with the eleventh a compact club 

 which is much thicker than the ninth segment. Prothorax distinctly 

 longer than broad, nearly cylindrical, lateral dilation weak. Elytra broader 



