494 NEW YORK STATE MUSEUM 



6 Cross section of hypopharynx. xllO ] 



7 Wing of male. xl5 



8 Thoracic respiratory filaments of pupa. xl5 i 



PLATE 37 ; 



Simulium venustum and varieties ) 



1 Maxilla of larva. xllO 



2 Hypopharynx of larva, var. piscicidium. xllO 



3 Labrum of larva, venustum. xllO 



4 Respiratory filaments of pupa. x40 



5 Labium of lai'va, var. piscicidium. xl90 



6 L<abium of larva, venustum. xl90 j 



7 Respiratory filaments of pupa, var. piscicidium. xllO j 



8 Wing of imago, var. a 



9 Caudal api>endages (blood gills) of larva, var. a. xllO 



10 Hypopharynx of larva, var. a. xllO 



11 Thoracic respiratory filaments of pupa, var. a. xllO , 



12 Labrum of larva, var. a. xllO ! 



13 Mandible of larva, var. a. xllO I 



14 Labium of larva, var. a. xl90 ! 



PLATE 38 ! 



I 



Legs. x50; claws. xl90 



1 S. venustum (var. p i s c i c i d i u m). Hind tai-sus ot male 



2 S. venustum (var. piscicidium). Middle tarsus of male i 



3 S. venustum (var. p i s c i c i d i u m). Fore tarsus of male 



4 S. venustum (var. a) Fore tarsus of female •. 



5 S. venustum (var. a) Middle tarsus of female ,' 



6 S. venustum (var. a) Hind metatarsus of male 



7 S. pecuarum. Hind metatarsus of female 



8 S. p i c t i p e s . Hind metatarsus of male 



9 S. vittatum. Hind metatarsus of female 



10 S. h i r t i p e s . Hind metatarsus of female 



11 S. h i r t i p e s . Hind metatarsus of male | 



12 S. m e r i d i o n a 1 e . Male and female metatarsus { 



13 S. b r a c t e a t u m . Female metatarsus ' 



14 S. pecuarum. Claw of female " 



15 S. b r a c t e a t u m . Claw of female 



16 S. m e r i d i o n a 1 e . Claw of female . 



17 S. p i c t i p e s . Male 



18 S. m e r i d i n a 1 e . Male i 



19 S. venustum, vai*. piscicidium. Female 



20 S. p i c t i p e s . Female 



21 S. o c h r a c e u m . Hind metatarsus of female 



PLATE 39 



Corethra plumicornis .i 



1 Larva of C. plumicornis. xl2 ' 



2 Pupa of same. xl2 



2a Breathing tube of pupa. xllO ; 



