MAY FLIES AND MIDGES OF NEW YORK 285 



KEY TO SPECIES OF TANYTARSUS 

 Larvae 

 a Moderate sized pink or red species, with long filaments at the extremity 

 of antenna, pl.26, fig.la 

 6 With a hump on dorsal surface of last abdominal segment, most dis- 

 tinct in fresh specimens, pl.26, fig.5 ' 5. dives n. sp. 



hh Without this hump 3. gmundensis 



aa Small yellowish species, antennae without long filaments 



h Antennae with two delicate processes with slightly enlarged ends at 

 extremity of the second joint, pl.26, figs. 13-14 ; larva usually found 



in its fibrous case, pl.26, fig.9 13. e x i g u u s n. sp. 



hh Antenna with a pointed process at end of second joint, pl.25, figs. 

 16, 17 10. d i s s i m i 1 i s n. sp. 



Pupae 

 a Lateral fin of the eighth abdominal segment with a simple terminal spur, 

 pl.26, fig.l5 ; second abdominal segment with two small patches of setae 

 near the anterior end and a transverse row near posterior end ; pupa 



in a fibrous case, pl.26, fig.9 13. e x i g u u s n. sp. 



aa Lateral fin of the eighth segment with a comb 



& Fourth abdominal segment with two patches of short stout setae on 

 anterior end and a few scattered setae on the surface, pl.26, fig.7 



5. d i V e s n. sp. 

 &6 Fourth segment with two longitudinal rows of setae caudad of the 

 anterior patch 

 c With a transverse row of stout setae on posterior margin of third 



segment, pl.25, fig.20 10. d i s s i m i 1 i s n. sp. 



cc With two patches of setae near posterior margin of the third seg- 

 ment, pl.25, fig.18 Var". a. of d i s s i m i 1 i s 



Imagines 

 - a Thorax uniformly black or brown; thoracic stripes wanting or very 

 indistinct 

 h Legs white or pale yellow ; wings white ; thorax and abdomen subshin- 

 ing black ; male abdominal segments with paler posterior margins ; 

 fore metatarsus about 0.15 longer than its tibia 



1. b e d i e n s n. cp. 

 hi) Legs dusky yellow, fuscous, or black 



c Halteres black or dusky ; thorax and abdomen subshining black ; fore 

 metatarsus about 0.16 longer than its tibia 



2. n i g r i p i 1 u s n. sp. 



cc Halteres pale 



d Fuscous, including legs ; thorax subshining ; fore metatarsus over 



0.4 longer than its tibia 3. gmundensis 



dd Smaller dark brown or fuscous green species; fore metatarsus 

 less than one fourth longer than its tibia 



4. d e f 1 e c t u s n. sp. 



