NORTH AMERICAN COLEOPTERA. 
163 
elytral tip. Two species, Harrisu and distincta, present also the 
peculiar sinuation of the sutural margin of the elytra which charac- 
terizes that group. This consists in the displacement of the margin 
for a space equal to one-fourth the length of the elytron, whereby, 
wdien the elytra are closed in i-epose, an elliptical space is formed 
hounded by the displaced margins. In Harrisii the margin appears 
double, and the inner sinuate portion is in a higher plane than the 
outer straight portion. In most of the species the material which 
fills the sinuation is in the same plane. 
Eyes of normal size; sutural margin of elytra straight, except in distincta. 
Thorax punctate, not or scarcely tuberculate. 
Thoracic punctures coarse, uniform siiblilis. 
Thoracic punctures uneven, finer punctures mixed through the coarser. 
poroi^ioollis. 
Thorax uneven on the disc, tuberculate on the sides. 
Sutural margin of elytra straight. 
Elytra with two transverse indentations cPqiialis. 
Elytra not indented ; posterior femora male dentate, female simple. 
t II bore II lata. 
Sutural margin of elytra sinuate distincta. 
Eyes small; thorax tuberculate; sutural margin of elytra sinuate.... Harrisii. 
Of these species, porosicolUs seems rare ; the specimens I have are 
far more slender than any other, and there is an appearance of an 
abrupt demarkation on the sides of the elytra. Inasmuch as siibtilis, 
its nearest ally, is constant in the style of its punctuation, I have 
preferred to use that character for the separation of the two species. 
1'he specimens under subiilis may be separated thus : 
Thorax straight on the sides; second and third antennal joints subequal. 
Thorax constricted at middle ; third joint of antennse longer than second,..r!tgos«. 
but on account of the variations observed in these characters in other 
species, I doubt rugosa being a distinct species ; torosa Lee. is included 
with distincta. 
Group D. 
The species here included are readily distinguished by the convex 
form, rounded elytra and sinuate sutural margin. They may be 
se])arated as follows : 
Thorax depre.ssed without basal and medial groove. 
Posterior femora dentate in both sexes piisilla. 
Posterior femora dentate in male only Icinoralis. 
Thorax convex, punctured, and with an evident basal and more or less evident 
medial groove. 
