MAY PLIES AND MIDGES OF NEW YORK 285 



KEY TO SPECIES OF TANYTAESUS 



Larvae 

 a Moderate sized piok oi' red species, with long filaments at the extremity 

 of antenna, pl.26, fig.la 

 h With a tiump on dorsal surface of last abdominal segment, most dis- 

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



&?> Without this hump 3. gmundensis 



o« Small yellowish species, antennae without long filaments 



I) 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. 



&b Antenna with a pointed process at end of second joint, pi. 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.15 ; 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 



h 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. 

 hh 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 uniformlj' 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. o b e d i e n s n. cp. 

 hh 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. 

 CG 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. 



