NORTH AMERICAN COLEOPTERA. 
167 
to an entirely ditierent insect belonging to the last group. The va- 
riations observed are in size, as indicated above ; in color, which may 
be a uniform greenish black, or a much lighter color almost testace- 
ous, or a combination of both ; in the femoral teeth, which depend 
in number and size upon the development of the insect, and may be 
traced through gradually weakening forms, from three prominent 
spines in the male to a single obtuse tooth in the female ; and in the 
relative length of the antennal joints, the third being usually as 
short as the second, but sometimes evidently longer. It is never 
twTce as long, however, as in the following species. Although se- 
lected specimens can be made to look very different, I can find no 
character in these variations to base even a variety. 
With the punctuation of the thorax, it is somewhat different. In- 
termediate specimens do occur, and indicate the close relation be- 
tw’een cincticornis and its varieties proxima and magnijica, but the 
greater number are readily separated, as indicated in the synopsis. 
Food-plant is undoubtedly the pond lily, Nuphar advena. I have 
always found the insect on this plant, frequently within its yellow 
flowers, and Mr. Roberts has also in Vermont, and Mr. Blanchard 
in Massachusetts. Furthermore, it does not occur in localities where 
there are no lily ponds. The white water lily, Nymphcea odorata, 
occurs in many ])onds with the Nuphar, and the insects show no 
partiality for it in the imago stage. The original descriptions of the 
varieties are : 
Var. proxiina Kirby. — “Thighs bidentate, witli one tooth minute; above 
dark violet glossy, head rather bronzed ; punctures of the elytra green gilt; body 
underneath covered with a satin silver pile. Length 5 lines. Taken in Canada 
by Dr. Bigsby. Body a little flattened, covered uuderneatb with a dense coat 
of glittering silver pile resembling satin. Head a little bronzed, channeled 
between the eyes, minutely punctured, palpi testaceous ; antennae entirely black ; 
prothorax in the disc dark violet and channeled, sides bronzed and impressed, 
anterior tubercles not prominent; scutellum bronzed ; elytra nearly black, with 
a slight tint of violet, punctures green gilt, interstices of the rows not wrinkled, 
an anterior impression near the suture, rounded at the apex; posterior legs long, 
with the thighs somewhat curved, attenuated at the base, curved at the apex, 
with two teeth placed consecutively, the first long, slender and acute; the last 
wide, short and denticulated posteriorly. This species is nearly related to cras- 
sipes Fab., but the antenuse and legs are entirely black, and the teeth on the 
posterior thighs are not equal.” 
Length 8 — 11 mm. ; .32 — .44 inch. Habitat. — Cal., Idaho, Hud. Bay Terr., Can., 
N. H., Mass., N, Y., Pa., Wis. 
Abundant, over forty specimens before me, none of which are 
testaceous in color. 
