MAY FLIES AND MIDGES OF NEW YORK 



185 



Imago, male. Front and epistome yellow, palpi fuscous, shorter 

 than the antennae, its first joint about 1.5 times as long as broad, 

 the second twice, the third three times and the fourth four times 

 as long as the first. Antennae fuscous, 14-jointed, the first disk- 

 like, the second longer than broad, the third to the thirteenth 

 about as long as broad, the fourteenth longer than all the others 

 taken together; all furnished with long brown hairs except the 

 apical one-fourth of the fourteenth. Dorsum of the thorax black- 

 ish ; yellow on the humeri and pleura, covered with a white bloom, 

 most conspicuous on the humeri. The dorsum of the thorax has 

 a dirty yellow ground color, but the three black longitudinal 

 stripes are so wide that only a little of the ground color shows, 

 excepting on the humeri and the two very narrow faint longi- 

 tudinal stripes separating the three wide, black ones; the scutel- 

 lum is chestnut; metathorax black; pectus brown; abdomen dull 

 black, the dorsurn of the first two segments greenish ; the extreme 

 edge of each segment, paler fuscous; the venter greenish, darker, 

 almost black on the more posterior segments. The green is sharply 

 separated from the dorsal color on a lateral line. In dried speci- 

 mens this green color becomes duskj-; legs almost black, the coxae 

 and the bases of the femora yellowish, fore tarsi only pubescent, 

 not hairy; fore metatarsus about three fourths as long as the 

 tibia; tarsal claws simple; wings hyaline, hairless, the anterior 

 veins yellowish, the rest hyaline, venation as in fig.12, pl.30 ; ante- 

 rior and posterior margins delicately ciliate; genitalia inconspic- 

 uous. Halteres white. Length 3 to 5 mm. 



Female. Antennae seven-jointed, black, with short hairs. 

 Thorax with black stripes a little narrower than in the male, 

 hence the yellow stripes separating them and those on the humeri 

 more conspicuous. Pectus, scutellum, and a little space in front 

 of the latter brown; the pectus in dried specimens sometimes 

 nearly black; pleura yellow, metanotum black; abdomen as with 

 the male, but the venter is paler; legs black, coxae and bases of 

 femora yellow; tarsal claws simple; wings hyaline, anterior mar- 

 gin and tip a little dusky; anterior veins yellow; wing margins 

 delicately ciliate; venation as with the male; halteres white. 

 Length 3 to 5 mm. Many captured and bred specimens. Ithaca, 

 N.Y. 



2. Thalassomyia platypus Coquillett 



1902 Orthocladius Coquillett. Proc. U. S. Nat. Museum. 25 : 93 



Black, a large dull yellowish humeral spot, halteres, trochanters, 

 and extreme bases of femora yellow ; hairs of antennae dark gray, 

 thorax opaque, grayish pruinose ; tarsi only pubescent, the fourth 

 joint dilated, emarginate at the apex, noticeably shorter than the 

 fifth, first joint of front tarsi three fourths as long as the tibiae; 



