11 



and mesopleurae ; but there is no trace of bristles or long bristly hairs 

 anywhere on the thorax or scutellum. 



Wings without any markings or bands, hyaline, somewhat infu- 

 mate ; in life the wings are extended half open when at rest. Venation 

 quite in accordance with the typical form of the Tabanidae, except 

 that the upper branch of the cubital fork has sometimes (in dorsalis 

 Coq.) a recurrent veinlet near its base ; all the posterior cells open 

 widely ; anal cell slightly open or distinctly closed. Squamae some- 

 what large, with very slight fringes. Halteres with the knob large 

 and almost globular. 



Legs with two apical spurs on both the middle and hind tibiae ; 

 fore coxae long, slightly longer than half the length of the femora ; 

 femora a little shorter than the tibiae. Pubescence fairly abundant on 

 both the fore-coxae and femora. Pulvilli three, distinct. 



Abdomen moderately long, scarcely broader than the thorax 

 but slightly narrowed behind, composed of seven segments ; second 

 segment longest, and the fallowing ones gradually diminishing in length ; 

 surface of the abdomen unicolor without any markings or bands. 

 Genitalia small and usually inconspicuous. 



This genus is composed of a small number of species which 

 occur in Europe and America, and it is known to extend through 

 Africa to Madagascar, in Asia, Asia minor, Morocco, Japan, Formosa and 

 India, and in Australia and New Guinea. About 47 species occur in 

 the whole world, including about six species which have been des- 

 cribed as from oriental region ; at the present time, we know only two 

 Japanese species, but one of these has been only recently described 

 from Formosa. 



Key for Species. 

 I. Small-sized species, without callus on the frons . . 



fonuosiensis Ric. 



