106 BULLETIN 6.3, UNITED STATES NATIONAL MUSEUM. 



sexes, first joint slightly thickened and feebly })rodiiced at tip be- 

 neath with a tuft of spinules interrupting the groove. 



Male. — Oblong-oval, somewhat elongate. Antenna^ reaching to the 

 posterior fifth of the prothorax. Elytra usually widest at the base 

 and thence arcuately narrowing to aj)ex. Abdomen slightly oblique, 

 moderately convex, distinctly impressed at base of the first segment 

 and between the coxse. Anterior spur of the anterior tibia about one- 

 half to one-third longer than the posterior, gradually tapering from 

 base to apex, and acute. First joint of each anterior tarsus with a 

 small, subacute tuft of yellowish modified pubescence on the produced 

 tip beneath; second joint slightly thickened at tip beneath with a 

 similar and rather incons2:)icuous tuft; groove interrupted. 



Female. — Oblong, robust. Antennae reaching to the posterior 

 fourth of the prothorax. Elytra broadly oval and usually widest at 

 the middle, scarcely narrowed but more or less arcuately rounded pos- 

 teriori}". Abdomen horizontal and rather strongly convex. Anterior 

 spur of the anterior tibia about twice as long as the posterior, curved, 

 distinctly broadened, with sides quite parallel, somewhat narrowing 

 at tip. First joint of an anterior tarsus with a tuft of ordinary pic- 

 eous spinules on the thickened tip ; second joint unmodified. 



The present species is quite variable, and I deem it proper to indi- 

 cate four incipient races, as follows : 



Forma typica. — Slightly elongate in form, pubescence usually pale 

 fiavate in color. Elytra distinctly flattened, normal costa* well devel- 

 oped, the intermediate completely obsolete or ver}^ feebly indicated, 

 intervals broad and flat. 



Forma ovalis. — Oval, short and robust in form. Pubescence 

 usually black. Elytra rather strongly convex, normal costae well 

 developed and somewhat glabrous and shining, intermediate costse 

 more or less evident. 



Forma costata. — (ieneral form as in typiva but smaller. Elytral 

 costcT more or less strongly and quite equally developed. 



Forma robusta. — Form broadly oblong, large. Elytra more or 

 less convex, all of the costw more or less developed, rather coarsely 

 muricate, at apex becoming subspiculiferous. 



Measurements. — Males: Length, LV22.5 mm.; width, 6.5-10.5 mm. 

 Females: Length, 14-22.5 mm.; width, 7-11.5 mm. 



Genital characters^ male. — Edeagophore flaxseed-shaped, slightly 

 elongate and not arched. 



Basale oblong, evenlj?^ convex and more or less gibbous in basal half; 

 sides evenly arcuate. 



Aficale triangular, slightly elongate, feebh^ arched ; dorsal surface 

 evenly convex, Avith a moderately wide median membranous groove 

 in apical half; sides feebly arcuate or nearly straight ; apex subacute; 

 base more or less broadly arcuate, scarcely sinuate laterally. 



