AQUATIC INSECTS IN NEW YORK STATE oes yi 
d Posterior femora pedunculate; thorax closely punctulate 
e Legs dark 
f Posterior femora dentate in both sexes...... emarginata 
ff Posterior femora dentate in the male only..... metallica 
ee Legs rufo-testaceous; posterior femora dentate in both sexes 
flavipes 
dd Posterior femora elliptical, dentate in both sexes; thorax sparsely 
punebured legs rufO-teStACeOUS.... oc ..be se ce ceelee wba rufa 
Donacia cincticornis 
Egg. 5mm long, rounded at each end, the sides subparallel, 
slightly concave on one side and convex on the other, naked, 
laid in an irregular mass on aquatic plants, and attached by one 
-end [pl.21, fig.3; pl.24, fig.3]. 
Larva. Mandibles bidenticulate with a few crenulations with- 
in [pl.25, fig.1]; eyes apparently wanting; all the segments of 
the leg with only a few setae, the basal segment with eight to 
10, each of the others with three or four [pl. 25, fig.8]; the 
labrum four sided, emarginate in front with eight marginal 
setae, the two lateral ones of each side distant from the median 
ones and from each other, with six discal setae, the distal pair 
about one half the length of the median pair, the proximal pair 
as long as the distal and median pairs together, two lateral 
setae, each extending beyond the front margin of the labrum, 
and two sensory pits [p1.25, fig.6]; the anterior tergal setae of 
the mesothorax and metathorax divided into three well marked 
groups, those of the first six abdominal segments straight and 
broad and not divided, those of the seventh segment consisting 
of an irregular row of setae; the posterior tergal setae of the 
first six abdominal segments of about the same length as the 
' anterior tergal setae, those of the seventh abdominal segment 
almost as long as the width between the spiracles; the su- 
praspiracular setae of the first six abdominal segments broad* 
and well marked and coalesced with the lateral extensions of 
the anterior tergal setae, and not coalesced with the lateral 
extensions of the posterior tergal setae; those of the seventh 
abdominal segment consisting of three or four setae and hardly 
more than a continuation of the anterior tergal setae; the in- 
fraspiracular setae well marked, triangular in outline, becom- 
ing smaller caudad; the anterior and posterior sternal setae 
of the prothorax broad and separated, those of the mesothorax 
and metathorax broad and separated except at middle, the 
1By this expression is meant not a single setae, but the group of setae 
known as the supraspiracular setae, and it is used in this sense through- 
out. 
