ORIENTAL SPECIES OF TABANUS 



277 



usually one or two small raised knobs or bands of a dark colour, the 

 calli ; the lower of these may be transverse or broadened transversely, the 

 upper round or oblong ; in the majority of species one of these is produced 

 upwards to the vertex as a narrow line; rarely both are so produced. 

 One or both of the calli may be absent. The antennae are three-jointed 

 and are shorter than the head ; the proximal joint is short, the second 

 very short, only about one-third as long as the first, the distal joint as 

 long as the first and second together. The third joint is styliform, 

 consisting of four segments, and has a dorsal spine or hook at its basal 

 end. The thorax is broad, and often has longitudinal stripes. The 

 abdomen is slightly broader than the thorax, and may be banded with 

 stripes or only marked with spots. The wings are large, and usually 

 clear, but there may be spots and bands. The anterior branch of the 

 third longitudinal vein may or may not have a backwardly directed spur. 

 Miss Ricardo gives the following table of the Oriental species of 

 Tabanus : 



TABLE OF GROUPS 



I t Eyes bare .......... 



Eyes hairy (Thcrioplcctes) ....... 



II. Forehead with two separate calli, the first one usually 

 transverse, the second irregular in shape, smaller. Fore- 

 head four to six times as long as it is broad. Small 

 species 9 to 14 mm. in length ..... 



IH Thorax and scutellum same colour. Abdomen with no 

 bands .......... 



Scutellum white or yellow-haired. Abdomen with white 

 or yellow-haired bands ....... 



IV. Forehead with two small round spot-like calli, one above 



the other, never united 



V. Forehead with no callus ....... 



VI. Forehead with one square, narrow, or oblong callus, which 

 is always prolonged towards the vertex by a more or less 

 narrow line . . 

 VII. Wings with spots or bands ....... 



Wings distinctly marked with brown or yellow colouring, 

 but not in the form of bands. Large species 18 to 23 mm. 

 in length .......... 



Species with one or more stripes, usually continuous, on 

 abdomen. Forehead five to nine times as long as it is 

 broad ........... 



Species with median or lateral spots or both on abdomen, 

 not usually forming a continuous stripe. Forehead four 

 to ten times as long as it is broad ..... 



II 



GROUP XI 



III 



GROUP I 



GROUP II 



GROUP HI 



GROUP IV 



VII 



GROUP V 



GROUP VI 



GROUP VII 



GROUP VIII 



