AQUATIC INSECTS IX NEW YORK STATE 315 



* Supraspiracular setae of the first six abdominal segments forming a 

 single continuous group of setae 

 « Sternal setae of the fifth abdominal segment divided longitudinally 

 by a mesal line into two groups; the posterior sternal setae of the 

 mesothorax undivided 

 d Sternal setae of the seventh abdominal segment distinctly di- 

 vided into two groups ; the inf raspiracular setae of the seventh 

 abdominal segment not longer than broad. ..cincticornls 

 4d Sternal setae of the seventh abdominal segment continuous; the 

 infraspiracular setae of the seventh abdominal segment twice 



as long as broad p a 1 m a t a 



CO Sternal setae of the fifth abdominal segment not divided; the pos- 

 terior sternal setae of the mesothorax not divided longitudinally 

 into two groups 

 d Supraspiracular setae of the sixth and seventh abdominal seg- 

 ments coalesced with the outer ends of their posterior tergal 



setae subtllis 



dd Supraspiracular setae of the sixth and seventh abdominal seg- 

 ments not extending as far caudad as the posterior tergal setae 



porosicollis 

 66 Supraspiracular setae of the first six abdominal segments divided 



transversely into two well marlied groups aequalis 



na Supraspiracular setae of the first five abdominal segments extending 

 caudad as far as the caudal margin of the posterior tergal setae 



emarginata 

 Pupa 



a Antennae with the third segment distinctly longer than the second 



p al m a t a 

 aa Antennae' with the second and third segments subequal 



6 Prothorax distinctly tuberculate on the side; the pronotum with an 



impressed line at middle aequalis 



*6 Prothorax not tuberculate on the side; the pronotum not with an 

 impressed line at middle 

 c First abdominal segment as long as, or longer than, the next four 

 segments 

 d Mesosternum between the coxae nearly as broad as the coxae 



cincticornls 

 dd Mesosternum between the coxae about one half the width of the 



coxae or less subtllis 



CO First abdominal segment as long as the next three segments 



emarginata 

 Imago^ 



a Head and thorax evidently pubescent above 

 6 Elytra without pubescence 



c Posterior femora with a small tooth h 1 r t i c o 1 1 1 s 



CO Posterior femora simple pubicollls 



66 Elytra evidently pubescent; posterior femora toothed, .pubescens 



iThis table was compiled from a table by Charles W. Leng. Bevlslon 

 of the Donaciae of Boreal America. Am. Ent. Soc. Trans. 1891. 17:159-7«. 



