494 NEW YORK STATE MUSEUM 



6 Cross section of hypopliarynx. xllO 



7 Wing of male. xl5 



8 Thoracic respiratory filaments of pupa. xl5 



PLATE 37 



Simulium venustum and varieties 



1 Maxilla of larva. xllO 



2 Hypopliarynx of larva, var. piscicidium. xllO 



3 Labrum of larva, venustum. xllO 



4 Respiratory filaments of pupa. x40' 



5 Labium of larva, var. piscicidium. xl90 



6 Labium of lai-va, venustum. xl90 



7 Respiratory filaments of pupa, var. piscicidium. xllO 



8 Wing of imago, var. a 



9 Caudal appendages (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 



14 Labium of larva, var. a. xl90 



PLATE 3S 



Legs. x50; claws. xl90 



1 S. venustum (var. p 1 s c i c i d i u m). Hind tarsus of male 



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



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. pietipes. 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. pietipes. Male 



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



19 S. venustum, var. piscicidium. Female 



20 S. pietipes. Female 



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



PLATE 39 



Corethra plumicornis 



1 Larva of C. plumicornis. xl2 



2 Pupa of same. xl2 



2a Breathing tube of pupa. xllO 



