AQUATIC IXSECTS IX NEW YORK STATE 319 



and indistinctly connected with the siipraspiracular 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 the 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, bmt 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 segments 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 furrow 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 ad vena. Length, llmm ; width, 5mm. 



Described from numerous specimens collected by J. O. Martin 



and the writer on the stems of Nymphaea advenaat 



Ithaca N. Y. 



Donacia subtilis 



Larva. Mandibles bidentate, the inner margins hardly crenu- 

 late [pl.25, fig. 15] ; eyes present, five in number, arranged in two 

 rows [pl.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.25, 



