MAY FLIES AND MIDGES OF NEW YORK 289 



overhanging setae, and the transveriSe comb, the latter having a 

 number of uniform rather long, slender, caudad projecting teeth. 

 Gaudad of this are three hand-shaped processes, each with five or 

 six slender, apical, finger-like projections. The lateral arms are 

 prominent, and have enlarged, bifid extemities. Each mandible 

 has a stout subapical and mesad projecting seta, a fringe of sub- 

 apical hairs, and a slender dorsal, laterad projecting seta (fig.2). 

 The maxilla (fig.4 mx) has a comparatively long palpus (p), a 

 number of small papillae and setae and some mesad curved spines. 

 The hypopharynx has the usual fringe of fine hairs and papillae 

 (fig.4 hy). The labium (1) has about 13 blunt, rounded teeth, the 

 middle one most prominent. 



The anterior prolegs have numerous curved, slender, hair-like 

 setae. In nearly mature specimens the thorax is somewhat en- 

 larged. The body has few if any setae. The last segment (fig.5), 

 has a prominent hump near the anterior margin; the posterior 

 prolegs are rather prominent, with a small number of stout claws ; 

 each of the dorso-caudal setae tufts is mounted on a prominence. 

 The anal gills are four in number and comparatively short, about 

 twice as long as wide. The larva makes a rough, loose, cylindrical 

 case which partly conceals it. 



Pupa. Length 4 to 5 mm. Dusky, with the thoracic respira- 

 tory organs each consisting of a single slender shaft, with lateral 

 hairs (fig.3), about as long as a single abdominal segment. The 

 dorsal surface of the abdomen is marked with minute setae, 

 spines, and hairs, as shown in fig.7. This figure shows segments 

 two to six inclusive. The dorsum of the second segment is nearly 

 uniformly covered with fine, very short, miscroscopic spines, four 

 or five pairs of pale setae and the usual chitinous, longitudinally 

 ridged, posterior margin; the third has anteriorly two patches 

 of short black spines, two patches of fine hairs, the rest of its 

 dorsal surface punctate with minute spines, and five or six pairs 

 of pale setae; the fourth, fifth and sixth segments each have two 

 dense patches of short black spines near the anterior margin, 

 sparsely punctate with minute spines, and provided respectively 

 with about eight, seven and five pairs of pale setae. The eighth 

 segment (fig.6) has the usual lateral fins, with its filaments, and 

 has also the combs, each with five or six prominent black teeth. 

 The caudal fin is fringed with long,, pale, matted hairs. 



Imago, male. Dusky brown, sometimes blackish, legs yellow- 

 ish brown; length 3.5 to 4 mm. Head, palpi, proboscis and an- 

 tennae brown, the hairs of the last also brown. Dorsum of 

 thorax gray pruinose, with three subshining brown or black 

 stripes, humeri sometimes a little yellowish. The pleura, sternum 

 and metanotum subshining black, the last with a narrow longi- 



