BY ARTHUR WHITE. «* 



16. T a b a n u s, L. (Fig. 12a). 



Face broad. Eyes either bare or pubescent, joined in 

 the male, separated in the female. Proboscis and palpi 

 produced. Antennae about as long as the head, the first 

 joint short, but longer than the second, the third with 

 the basal segment large and dorsally humped, with four 

 subsequent annulations. Thorax large, quadrate, with 

 rounded angles. Abdomen about as broad as, but hardly 

 longer than, the thorax. Legs simple; middle tibiae with 

 two apical spurs; front and hind tibiae without spurs. 

 Wings occasionally, though rarely, spotted ; posterior cells 

 usually open ; anal cell closed ; alulae and squamae well 

 developed. 



The Tasmanian and Victorian species of Tabanus fall 

 into two natural groups. In the first of these, which 

 contains only a few species, the cubital fork of the wings 

 is without a recurrent veinlet, the eyes are sparsely hairy 

 in the female, densely hairy in the male, and the abdo- 

 men is unusually broad and flattened ; in the second group 

 the cubital fork of the wings possesses a recurrent veinlet, 

 the eyes are densely hairy in both sexes, and the abdomen 

 is not as a rule so flattened. In none of the Tasmanian 

 species is the dorsal hump of the antennae much developed, 

 indeed in some species the antennae are almost symmet- 

 rical ; this character divides them from most of the West 

 Australian, and some, at least, of the North Australian 

 species, in which the antennal hump is greatly developed. 



The species of T aha mix are difficult to identify, many 

 of them being very nearly allied, and possessing few dis- 

 tinguishing characteristics. The most important charac- 

 ters (in Australian species) are the presence or absence 

 of a small recurrent veinlet to the cubital fork, the shape 

 of the frontal stripe (between the eyes) and the form 

 •of the antennae. Another character that is sometimes of 

 considerable value is the comparative length of the pubes- 

 cence on the legs, more particularly that of the tibiae. 

 The colouration is often subject to considerable variation, 

 but the size of a species, fortunately, varies but little. 

 A character that must be used with caution is the presence 

 or absence of a row of central abdominal spots; probably 

 all species possessing the recurrent veinlet have these spots 

 when in perfectly fresh condition, but in some species 

 they are lost very readily. The length of the proboscis, 

 also, is not always a reliable character. 



In the following descriptions, "frontal stripe" refers to 

 the portion of the front between the eyes in the females ; 

 in the males the eyes join, and the frontal stripe is there- 

 fore wanting ; "frontal triangle" refers to the portion of 



