AQUATIC INSECTS IN NEW YORK STATE 319 
and indistinctly connected with the supraspiracular setae, those 
of the sixth and seventh segments not attenuated laterally, and 
distinctly separated from the supraspiracular setae, the anterior 
tergal setae of the seventh segment not more than one half the 
width of those of ithe other segments, the posterior tergal setae 
of the seventh segment broad and continuous; the supraspiracu- 
lar setae of the first six abdominal segments transverse, well 
marked, but not extending caudad as far as the posterior tergal 
setae, those of the seventh abdominal segment but little broader 
than the band of anterior tergal setae; the infraspiracular setae 
broad and somewhat oblique; the anterior and posterior sternal 
setae of the thoracic segmenits distinctly separated, the posterior 
sternal setae of the prothorax divided longitudinally, the sternal 
setae of the first four abdominal segments broad and continuous, 
those of the fifth and sixth abdominal segments smaller and. 
divided longitudinally, those of the seventh abdominal segment 
forming an almost continuous but attenuated band at middle, 
and coalescing at its outer ends with the pedal setae; the pedal 
setae of the first six abdominal segments well marked and dis- 
tinct, not coalesced with the sternal setae [pl.29, fig.2]. 
Pupa. White; legs, wing-pads, and antennae not closely 
attached to the body; the third segment of the antennae almost 
twice the length of the second; pronotum with an indistinct 
median furrew and not tuberculate on the sides in front; the 
first ventral abdominal segment as long as the next three. 
Length, 11mm; width 5mm. 
Cocoon. Brownish; oval in outline; and attached in groups of 
three or four on the leaf scars of the underground stems of 
Nymphaea advena. Length, 11mm; width, 5mm. 
Described from numerous specimens collected by J. O. Martin 
and the writer on the stems of Nymphaea advena at 
Tihaca N, Y. 
Donacia subtilis 
Larva. Mandibles bidentate, the inner margins hardly crenu- 
late [pl.25, fig.15]; eves present, five in number, arranged in two 
rows [p1.25, fig.13]; the three segments of the legs with numer- 
ous large setae of varying lengths [pl.25, fig.14]; the labrum 
distinctly five sided, with eight marginal setae, the outer dis- 
tinctly longer than the six inner, which are subequal in size and 
adjacent and distinctly separated from the lateral marginal 
setae, with six discal setae, the proximal pair long and slender, 
the median and distal pairs almost in a line, the median pair 
the longer, with two lateral setae which are as stout and as long 
as the proximal discal setae, and with two sensory pits [pl.29, 
