MAY FLIES AND MIDGES OF NEW YORK 293 



a pair of discal setae. The lateral fin of the eighth segment 

 terminates in a comb with six or seven short black teeth. The 

 caudal fin is elongate and has the usual fringe of matted hairs. 



Imago. Differs from T . e x i g u u s n. sp. in being darker, 

 in having a shorter metatarsus, and in the form of the male gen- 

 italia. It is yellowish green, sometimes nearly wholly yellow, 

 more or less infuscated, with three brown thoracic stripes. 



Male. Head yellow, including proboscis, palpi and the large 

 basal joints of the antennae; the antennae brown, the basal por- 

 tion of each hair appearing paler; eyes black. Thorax yellow, 

 slightly infuscated, with a greenish tinge, usually with three more 

 or less distinct buff or pale brown, sometimes darker, stripes. 

 Abdomen green, slender, yellow toward tip; genitalia elongate 

 (pl.33, fig.3), with a dorsal downward curved keel (d), and four 

 pairs of appendages; an elongated pair of lateral lobes (1), a pair 

 of inferior lobes (i) with rounded ends, a pair of short, blunt, 

 superior lobes (s) with much incurved ends, and finally a pair of 

 brush-like appendages (a) projecting mesad from the side of the 

 superior lobes. Legs hairy, uniformly light yellow, sometimes 

 slightly infuscated, tips of middle and hind tibiae each with a pair 

 of minute black combs with an elongate middle tooth, forming 

 a spur. Fore metatarsus about one half longer than its tibia. 

 Wings pale, hairy, the heavier veins close to the anterior margin, 

 all veins pale yellow. Halteres white. Length 1.75 to 2.25 mm. 



Female. Like the female of T . e x i g u u s n. sp. but is con- 

 siderably darker yellow; the thoracic stripes are brown, meta- 

 thorax brown, abdomen deeper green, the legs pale grayish yel- 

 low, sometimes fuscous. In dried specimens all colors appear 

 rather dusky. Length 1.25 to 1.75 mm. Proportion of metatar- 

 sus to its tibia like that of the male. 



This species was bred a number of times during May, July, and 

 October from pond water. Ithaca N. Y., Ottawa, Canada (from 

 Professor Fletcher) . 



Vor. a. Larva can not be distinguished from the foregoing; the 

 pupa differs in having fewer setae upon the dorsum of abdomen. 

 (See fig.18 for the arrangement of these setae.) This variety has 

 been bred several times. There seems to be no intermediate stage. 

 The adults of this variety seem to be a little more dusky than 

 those of the other. 



11. Tanytarsus fulvescens n. sp. 



(P1.30, fig.l9) 



Male. Testaceous ; segments of the abdomen brown with paler 

 posterior margins. Length 3 mm. Head with palpi, probocis, 

 and antennae, and its hairs brownish. Dorsum of the thorax, 

 pleura and scutellum testaceous, with cinereous reflections; the 



