NORTH AMERICAN COLEOPTERA. 
169 
M(xle, pygidiuni truncate; female, very elongate, roniulecl at tip; posterior 
femora dentate in both sexes, often bidentate in male. 
Length 9—11 mm.; .36— .44 inch. Habitat. — Pa., N. J., N. Y., lMa.ss.. Can., 
Mich., W is. 
Abundant on the pond lilies. The color is often testaceous. 
D. piseatri.v Lacordaire Original description translated. 
“Pale rufous, opaque; chest and head blackish; beneath cinereo-sericeous. 
Prothorax subtransverse, somewhat narrowed at base, anterior angles obsolete, 
the posterior distinct; bituberculate on each side, smooth above, impressed at 
base; the dorsal channel narrow, subobsolete. Elytra subparallel, apex declivous, 
broadly squarely truncate; disc flat, vaguely bi-impressed. punctato-striate ; tbe 
interstices slightly convex, subporcated, on all sides very slightly coriaceous. 
Length 44 lines; width lines.” 
Mesostenmm as broad as the coxa female, narrow'er male ; first ventral segment 
about as long as the raeta.sternum ; elytral tip subtruncate, not so squarely ter- 
minated as in the preceding; form more convex, making an approach to the 
convex forms of following groui)s ; antennse comparatively shorter and slightly 
stouter; femora dentate, middle tibiae unsymmetrically dilated at tip. 
Male, pygidium subtruncate; posterior femora strongly dentate or bidentate; 
first ventral segment excavated at middle, i.e., there is a depressed pit, such as 
the point of a dull pencil might have formed. 
Female, pygidium elongate, rounded at tip; posterior femora unidentate, first 
ventral not excavated. 
Varies in color from the typical “ pale rufous” to a dark bronze 
just as the preceding species do; alutacea Lee. is the name ap{)lied 
to the darker forms in many collections, but it is impossible to draw 
any line between them. The intermediate forms are among the most 
beautiful specimens in the genus, the suture being broadly bronzed 
and the other part of the elytra golden testaceous. 
This species occurs with the preceding on the leaves and in the 
dowers of Nuphar, and I have taken it on the roots of that plant, 
where it pupates, enclosed in an oval cocoon of leathery consistency. 
It is mixed in most collections with palmata, and the females are not 
readily separated. 
Length 6.5 — 10 mm. ; .26 — .40 inch. Habitat, — Cal., Wis., 111., N. Y., Ga., Fla., 
Texas. Abundant. 
I>. siibtilis Kunze. Dr. LeCoute’s description translated. 
“Depressed, elongate brassy; thorax densely rugosely punctate, quadrate, a 
little longer than wide, scarcely narrowed behind, angles prominent; more or 
less channeled, sides almost straight, scarcely impressed. Elytra tri -impressed, 
interstices flat; transversely densely rugose. Auteuuse with third joint about 
one and a half times as long as second. Posterior femora less elongate, strongly 
clavate, armed beneath with an acute tooth. Length .27 — .28. N. Y. and Pa. 
Varies cupreous metallic; varies also by the elytra being not impressed. Smaller 
specimens have the thorax deeply impressed.” 
Mesosternum narrower than the coxa, but wider in the female; first ventral 
segment longer than the metasternum; tip of elytra truncate, form broader in 
( 22 ) 
TRANS. AM. ENT. SOC. XVIII. 
•JULY, 1891. 
