494 NEW YORK STATE MUSEUM 



6 Cross section of bypopbarj-nx. xllO 



7 Wing of male. xl5 



8 Tboracic respiratory filaments of pupa. xl5 



PLATE 37 



Simulium venustum and varieties 



1 Maxilla of larva. xllO 



2 Hypopbarynx 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 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 Hypopbai*ynx of larva, var. a. xllO 



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



12 Labrum of larva, var. a. xllO 



13 Mandible of laiTa, var. a. xllO 



14 Labium of larva, var. a. xlOO 



PLATE 38 



Legs. x50; claws. xl90 



1 S. venustum (var. p i 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. p i c t i p e s . Hind metatarsus of male 



9 S. vittatum. Hind metatarsus of female -^ 



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



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



12 S. m e r i di 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 o n a 1 e . Male 



19 S. venustum, var. piscicidium. Female 



20 S. pictipes. Female 



21 S. ocbraceum. Hind metatarsus of female 



PLATE 3i) 



Corethra plumicornis 



1 Larva of C. plumicornis. xl2 



2 Pupa of same. xl2 



2rt Breatbing tube of pupa. xllO 



