MAY PLIES AND MIDGES OF NEW YORK 225 



lowish, sometimes with a slight greenish tint. In immature spe- 

 cimens the parts described above as dusky are more yellowish. 

 The fore metatarsus is about three fourths longer than the tibia. 

 Numerous female specimens. One bred specimen believed to be 

 the same, the pupa of which is described above. Ithaca, N. Y. 



41. Chironomus flavus n. sp. 



(P1.22, figs. 1 to 4 ; pl.28, fig.20 ; pl.32, fig.l2) 



Larva. No eggs were found. The larvae were taken in com- 

 pany with Thalassomyia fusca from the surface of the 

 rocks washed by swift flowing water. Some specimens of the 

 larvae found in August were placed in still water, and in due time 

 transformed and emerged, so that it appears that this species 

 will live in still water also. The full grown larva is pale yel- 

 lowish green, with pale brown head. Length 6 to 7 mm. and quite 

 slender. The head is rather short, pale brown, the eye spots each 

 consist of a pair of contiguous spots, conspicuously black, and the 

 black ends of the mandibles show prominently. There are several 

 setae upon the head, one in front, one close to but mesad of the 

 eye and a pair on top of the head between the eyes ; besides these 

 there is a transverse row of about 6 setae a little distance back of 

 the eyes. The antennae (pl.22, fig.la) are slender, about the 

 length of the mandibles; the first joint is about three 

 fifths of the whole length, the white apical process of 

 the first joint is nearly as long as the four apical joints 

 taken together. The two apical processes of the second 

 joint are about aS long as' the third joint. The labrum has 

 about six pairs of rather prominent pale setae, some of them 

 pectinate, and a pair of short pale fan-like processes at the apex. 

 The mandibles (fig.l md) are stout and have a densely black tip; 

 the maxilla (fig.l mx) has a prominent palpus, a pair of exceed- 

 ingly delicate slender mesad projecting processes with several 

 setae. The epipharynx has the usual pair of lateral arms, a trans- 

 verse comb composed of three hand-like processes, and the curved 

 pectinate hairs. The hypopharynx (fig.l hy) has the usual 

 papillae. The labium has a conspicuous black margin with the 

 tv\^o middle teeth longest, the first laterals much smaller, the 

 second laterals larger than the first, those laterad gradually de- 

 creasing in size outwards. The anterior prolegs have numerous 

 curved hairs, the posterior pair (fig.2) with numerous prominent 

 bilobed hooks. The ninth abdominal segment (fig.2) has the nor- 

 mal dorsal tufts of setae, four pale blood gills, of which the apical 

 two thirds of eac h is considerably smaller in diameter and pointed 

 at the apex. Dorsad of the upper pair is a pair of rather promi- 

 nent setae. 



