AQUATIC INSECTS IN NEW YORK STATE 317 



(l 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 



f 1 a V i p e s 



dd Posterior femora elliptical, dentate in both sexes; thorax sparsely 



punctured; legs mfo-testaceous r u f a 



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.2o, fig.l] ; 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 [pi. 25, fig.3] ; 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 [pl.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 



iBy 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. 



