MAY FLIES AND MIIXiKS OF XKW YORK 187 



Pupa. The pii]);i usually i-einaiiis within the tube constructed 

 by the lurva. but is capable of swininiing freely like a frog- larva. 

 It is jirovided with a pair of niurli branched thoracic filaments, 

 and its caudal segment is fringed Avitli long matted hairs or 

 filaments forming a paddle (pl.23, flg.Uf). 



Imago. The genus C h i r o n o m u s as restricted by Van der 

 Wulp (1874 and 1877, p.245) is defined by him in the latter work 

 as follows : Face usually hairy, lengtliened downward snout-like; 

 proboscis short, palpi bent, 1-jointed, the last joint elongated. 

 Antennae filiform, in the male 14-jointed, the first joint short, 

 disk-like, tlie second cylindrical, the following rounded, closely 

 sessile, the end joint very long and slender, all long and densely 

 plumose; toward the tip the hairs become gradually shorter; in 

 the female the antennae are much shorter, 7-jointed ; the first joint 

 short, disk-like, the second cylindrical, the following four oval, 

 sparsely haired, the last joint somewhat elongate. The eyes on 

 their mesal margin deeply emarginate, ocelli wanting: Thorax 

 liighly arched, more or less projecting over the head, flattened in 

 front of the scutellum, pectus very prominent, scutellum small; 

 metanotum well-developed; the markings of the thorax, if not 

 Tinicolored, consist of three, usually wide longitudinal stripes, of 

 which the median is posterioi-ly and the two laterals anteriorly 

 abbreviated ; sonietimes the median stripe is divided longitudin- 

 ally by a fine line, which continues to the scutellum. Abdomen 

 cylindrical, in the male sometimes flattened, the last or anal seg- 

 ment distinctly separated from the preceding, longer than broad, 

 the genitalia projecting tong-like, the claspers filiform or leaf-like. 

 Legs long and slender, jiarticularly the fore pair, of which the 

 tibiae are frequently very short, while the fore metatarsus is 

 always longer than its tibia ; the fore tarsi of the male are some- 

 times peculiarly haired; the tarsal claws and pulvilli upon all 

 the feet are small but distinct. The wings are bare, in the male 

 often shorter than the abdomen, the anal angle always present, 

 sometimes strongly projecting; subcostal vein delicate but dis- 

 tinct, as is also R^ Avhich enters the costa beyond the middle of 

 the wing; R^_i,-, emerges from the small crossvein, at its extremity 

 usually slightly curved downward, entering the margin not far 

 ironi the apex of the wing; the media is unbranched and joins 



