822 



and the four distinct lateral triangles therefore reddish yellow ; the pu- 

 bescence on the dorsum similar to that in the female but a little longer; 

 ventre usually pale yellowish red or yellowish brown on the four 

 basal segments, similarily dusted and haired as in the female. 



Length: 15-18 mm. 



Var. lateralis, n. (PI. VI, figs. 7 & 8 ; PL X, figs. 16 & 17). 



Head, thorax, legs and wings the same as in the typical T. 

 amaenus, but the dorsal abdomen of the female with reddish yellow lateral 

 stripes composed of oblique irregular spots on each segment from the 

 firt to the third or fourth, these spots situating on the side (where 

 the typical side-flecks should be) and more or less obscuring by a 

 yellowish grey tomentum and pubescence, and the ventral side with a 

 large obscured yellowish red spot between the first and second segments, 

 with a narrow transverse similar marking on the base of the third 

 segment, and with the irregularily situated slightly broader pale seg- 

 mentations ; the male usually with the more extended reddish yellow 

 lateral markings. 



I have good many specimens of this form, which were taken 

 by many collectors at several districts in Kiushu, from June to July. 



This species varies but little in the Formosan materials I have 

 seen, but apparently Japanese ones vary in the amount of reddish 

 brown colouring on the abdomen of the male (and the female of the 

 variety), and to a small extent in the practical absence of any reddish 

 colouring of the antennae in the female. It is allied to Tabanus nian- 

 darinus and T. takasagoensis (n. sp.), but is easily distinguished from 

 the latter by its much narrower frontal stripe, by its darker legs with 

 the tibiae conspicuously whitish, by its golden yellow pubescence on 

 the disc, of the thorax, and by its larger size ; and from the former 

 by its first posterior cell of the wings constantly closed with a long 

 petiole, by the three rows of triangles on the abdomen in the both 

 sexes, and by the reddish abdomen in the male. 



