258 



neither in Hokkaido. Sakhalin, nor also in Formosa and Riukiu 

 islands. 



11. Tabanns humilis, Coquillett. (PI. V. fig. g ; PI. 



X, figs. 10 & 1 1). 



(Ao-Ko-Alm). 



Proc. U. S. Nat. Mus., XXI, p. 311, 1898. 



Ricardo, Rec. Ind. Mus., IV, p. 240, 191 1. 



Kertesz, Cat. Dipt., Ill, p. 249. 191S. 

 Tabanns luridus. Fallen, fe^W^^^WtftMt^&J^M—Wi 



PI. VI, fig. 4. 1914- 

 Medium-sized blackish brown species, with two separated frontal calli 

 on the narrow frontal stripe, yellow subcallus, five very faint greyish 

 stripes on the thorax, conspicuously ashy grey tomentose scutellum, 

 whitish tibiae, and pale yellowish grey bands and median triangles on 

 the abdomen. 



Female. Head broader than the thorax, moderate in length, 

 and slightly arched. Frontal stripe covered with yellowish brown or 

 yellowish grey tomentum, am! more or less paler below, narrow and 

 contracting from the vertex to the front eye-angles, and wholly six 

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

 broadest part ; lower frontal callus blackish with the lower part some- 

 what yellowish brown, shining, very slightly convex, elongate square 

 with the somewhat straight margins of which the upper margin sometimes 

 irregularly notched and the lower margin often pointed below, and in 

 the middle there is more or less distinct longitudinal sulcus through 

 the whole length, separated from the subcallus by a rather narrow 

 dusted interval ; the upper frontal callus very narrow and elongate, 

 about as long as the lower one, sharply pointed in both ends, deep 

 black and shining ; frontal triangle moderately elevated and almost 

 wholly' occupied by yellow shining subcallus leaving a very narrow 



