Length : 10-12 mm. 



This species is not uncommon in mountainous districts through- 

 out Formosa Island, as I have records from Tentana, Taipin, Rukio, 

 Sokutsu, Horisha, Kosempo, and Mt. Rito, from July to September, 

 but it may be rather rare in the plain districts, only one having been 

 collected by H. Sauter at Hozan ; while the male is not captured yet 

 by any collecters. The female is known as a blood-sucker attacking 

 human beings, according to the late Dr. T. Kawakami's observation. 



10. Tabanus iyoensis, Shir. (n. sp.) (PL V, fig. 4 ; PI. X, figs. 8 & 9). 



Clyo-Sliiro-obi-Abu). 



Medium sized blackish brown species with yellowish shining 

 subcallus, two black separated frontal calli, white-haired scutellum, five 

 whitish yellow haired abdominal bands of which two are very distinct 

 and broader, and whitish tibiae. 



Female. Head large, slightly broader than the thorax, and very 

 slightly arched. Frontal stripe covered with ashy grey tomentum 

 which becomes slightly yellowish about the middle and slightly darker 

 above, rather narrow, slightly narrowed towards the frontal eye-angles, 

 but about equal in width through the vertical portion, and wholly seven 

 times as long as its narrowest part or four times as long as its broadest 

 part (between the vertex and upper frontal callus) ; pubescence on the 

 frontal stripe mostly black and rather conspicuous, but on the lower 

 portion (below the upper frontal callus) there are some rather incon- 

 spicuous yellowish white hairs, the black pubescence being rather 

 denser and much conspicuous towards the vertex ; lower frontal callus 

 blackish brown and shining but slightly yollowish below subquadrate 

 and slightly longitudinally elongate, or rarely transversely, with rather 

 straight lower margin but the upper margin laterally produced above, 

 separated from the subcallus by a narrow yellowish grey tomentose 

 interval, slightly convex and very often with an indistinct longitudinal 

 median sulcus ; isolated upper frontal callus very narrow but as long as 



