182 SIMCLIID^. 



Family SIMULIDXE. 



There is only one genus in this family, namely SimuHwm, though 

 Prof. Williston speaks of seeing a damaged North American 

 specimen that probably represents a second genus. 



From their short thick bodies, broad wings, short legs, and 



Fig. 22. Simulium. 



generally " squat " appearance the SIMULIIDJE are more unlike 

 the rest of the NEHATOCERA than any other group.* 



Their peculiar venation, however, which is totally unlike that of 

 any other family of Diptera, with the exception of the PHOBIC 

 in the BRACHYCEEA, will at once separate them, even to the 

 beginner's eye. 



Genus SIMULIUM, Latr. 



Simulium, Latreille, Hist. Nat. Ins. Crust, iii, p. 426 (1802). 



Simulia, auctt. 



Atractocera, Meigen, Klass. i, p. 94 (1804). 



GENOTYPE, according to Zetterstedt, S. reptans, Mg., but 

 Coquillet gives ETiagio colombaczensis, Schonb. 



Hea d semicircular. Eyes usually reniform,t sometimes rounded, 

 bare, in life generally of a red colour ; contiguous above in the 



* Excepting OEPHNEPHILID^;, which are not Oriental. 



t Zetterstedt (Dipt. Scand. ix, p. 3415) says the eyes in the male are 

 rounded, renifortn in the female. Insufficiency of material prevents my 

 confirming or disputing this ; most authors speak of the eyes as " rounded or 

 reniform," the inference being that the shape is not dependent on the sex. As 

 regards their colour Schiner says " generally red in life " ; Zetterstedt says 

 " often red in male, obscure in female." The latter author also notes sexual 

 differences in both antennae and palpi which are not recorded by subsequent 

 writers. 



