MAY FLIES AND MIDGES OP NEW YORK 295 



the tiny pupa. The case is shown on pl.26, fig.9. Ulmer (p.401, 

 1903) notes a similar structure for an European species. 



Larva. (P1.26, figs.8 to 15). The larva is pale greenish yellow, 

 with a brownish yellow head and elongate antennae; the length 

 is from 3 to 4 mm. Head about 1.5 times as long as wide, with 

 a number of short setae, two at the base of each antenna, two 

 on the front, one mesad, one laterad and one in front of each 

 pair of eyes. There are two eye spots on each side (figs.8 and 

 14) . The antennae (fig.13) are over one half as long as the head, 

 each mounted upon a lateral prominence. The first joint is three 

 times as long as the second, and has a seta on its side a little 

 distad of the middle, and an apical seta 1.5 times as long as the 

 second joint, the latter having two apical setae with rounded 

 ends. The third joint is shorter than the second, the fourth 

 is shorter than the third, the latter has a delicate apical seta. 

 All setae are very pale yellow in color. 'The labrum is prominent 

 and has two pairs of stout apical setae, one pair of which is 

 curved and elongated (fig.14) ; besides this there are five or six 

 pairs of smaller lateral setae. The epipharynx is like that of the 

 genus Chironomus, Avith the usual comb, curved setae, and 

 bifid lateral arms. The mandibles (md) have black tips, the max- 

 illae (figs. 12 and 14 mx) each have a prominent palpus and an 

 elongate mesad projecting process with several blades, very deli- 

 cate and transparent; the brown labium with its black teeth has 

 an outline as figured (fig.l2 1) . The pro legs have the usual curved 

 hairs. Each segment of the thorax has a very few scattered setae 

 arranged in two transverse rows. The abdomen is practically de- 

 void of setae. The last segment has the usual dorsal tufts of 

 setae, four short though conspicuous blood gills, and prolegs with 

 their retractile bilobed claws. 



Pupa. Pale yellow, with brownish thorax, length about 2.5 mm. 

 The respiratory organs are slender, unbranched, pointed fila- 

 ments, and bare; about one third the length of the thorax. The 

 second, third, fourth, fifth and sometimes the sixth segment of 

 the abdomen is dorsally marked with a pair of brown spots, upon 

 which are a number of short broAvn setae, near the anterior mar- 

 gin. The second segment has in addition a transverse row of 

 much finer microscopic spines near the posterior margin, and the 

 usual transverse ridged row upon the posterior edge (fig.ll). 

 There are also a very few scattered minute setae. Each lateral 

 fin of the eighth segment has four pale, slender filaments and a 

 single brown apical spur. The caudal fin has the usual fringe of 

 long matted hairs or filaments (fig.l5). 



Imago, male. Pale yellow, abdomen pale yellowish green. The 

 head with proboscis and palpi pale yellow; antenna somewhat 



