AQUATIC INSECTS IN THE ADIRONDACKS 



555 



from S. V i c a r i a in being much larger, according to the measurements 

 given in the extremely brief and uncritical published descriptions of that 

 species. There is a specimen from Illinois in the Museum of comparative 

 zoology, and I collected many specimens of both larvae and adults at 

 Lake Forest 111. in June 1899. I did not at that time rear the species, 

 however. I describe it below as Sisyra umbrata n. sp. 



In passing, I should call attention to an error almost uniformly com- 

 mitted in the characterizing of this genus : there is said to be no cross 

 vein in the basal part of the subcostal space. As a matter of fact, that 

 cross vein is almost always present, though it is sometimes not very dis- 

 tinct. I have examined specimens of three European species in the 

 Museum of comparative zoology, among them a large series of specimens 

 of the typical S. fuscata, as well as hundreds of specimens of the 

 species described below, and have not noted the absence of this cross 

 vein in a single case. 



Sisyra umbrata sp. nov. 



PI. 12, fig. 6, 7 and 33, 34, 36 text figures 



Length to tip of wings, male 6 mm ; female 8 mm ; expanse of wings, 

 male 12 mm, female 13 mm. 



Color nearly uniform blackish brown. There is a faint wash of rufous 

 on the face, the legs and the apex of the abdomen are dirty yellowish. 



Fig. 33 Fore wing of Sisyra umbrata 



Lake Forest 111. June 1899; Saranac Inn N. Y. June 28 to July 16, 

 1900; abundant. 



This is a stouter, larger, blacker, more hairy species than S. f u s c a t a. 

 The second segment of the antennae is nearly as large as the third and 

 fourth together, and the third is little more than half the size of the 

 fourth ; in S. f u s c a t a the second, third and fourth antennal segments 

 are subequal, and the third is not distinctly smaller than the fourth. In 



