MAY PLIES AND MIDGES OF NEW YORK 35 



base of the hind margin and a diagonal superior carina 

 strongly cliitinized. The purplish white-tipped gills are 

 clustered in small flat tufts of 2-3 times branched fila- 

 ments attached to the bases of the lamellae, and they are 

 shorter than the shortest of the lamellae. 'Setae stout 

 in basal half, w^lth dense internal fringes of taiwny hair. There 

 is a darker band across the middle beyond which the tips are 

 slenderer, and the fringes disappear, the whitish tips being bare. 



Color, rich chocolate brown above, paler below and on sutures, 

 a pale median stripe extending upward from the mouth over the 

 head and ending upon the prothorax. Tibiae and tarsi pale with 

 broad median rings of brown. 



The fore legs are Avidest apart and the middle ones most approx- 

 imate at base. 



The dates of my bred specimens are July 12, 14 and 19, 1901. 

 Trfansformation takes place at the surface of the water as in 

 other species, and the subimago stage continues about 24 hours. 

 On warm nights in midsummer subimagos swarmed into my 

 trap lanterns above Fall creek, Ithaca, but no imagos came to 

 them. Images were easily taken along the sides of the gorges 

 anywhere, sitting rigidly, their white fore feet extending full 

 length forward; so they would sit and allow themselves to be 

 picked up with the fingers. This is a fine species, interesting for 

 the agility of the nymph in the water and for the rich coloration 

 and striking attitude of the adult. 



Food. With a view to more accurately determining what is 

 the food of this species I had microscopic mounts made of the 

 cleared stomach contents of nine well-grown nymphs from Fall 

 creek. Plant remains constituted in all cases fully half of the 

 stomach contents — in some cases a much greater proportion. 

 There were recognizable remains of numerous C y a n o p h y- 

 c e a e and other algae, and numerous stalked diatoms of the 

 Gomphonema group (which may have been taken in with 

 the larger plant stems to which they were attached), but the 

 greater part was a brownish mass of remains of the decaying 

 leaves of higher plants. That Simulium larvae had been eaten 

 by four of the nymphs was determined by the presence of 

 isolated rays of the fans. Ecdyurus maculipennis 

 nymphs, common in the stream and of favorable size for the food 

 of this species, had been eaten by at least seven of the speci- 



