CYRTIDiE. 
595 
MS 
destruction is desirable since they are practically certainly concerned in 
the spread of diseases of horses and cattle. They can to a certain 
extent be kept from biting by the application of 
kerosene- or crude-oil emulsion, the effect some¬ 
times seeming to last for seyeral days after 
application. The family contains between one 
and two thousand species, which occur all over 
the world. Though the genera are very widely 
distributed, the range of many individual species 
seems to be comparatively restricted. The 
differences between the species are often ex¬ 
tremely slight, and the family as a whole shows 
a coherent assemblage of forms closely following 
one or two common patterns. It is thus very 
easy to recognise a fly as a Tabanid, and often 
difficult to find out what Tabanid it is. The 
table indicates the distinctions between the 
genera more commonly found in India. The 
number of species known is doubtful (Y. D. Wulp 
lists over fifty) and they are at present undergoing 
revision. All these genera are figured on PI. LXII. 
Antennae much longer than the head . . . . Chrysops. 
Antennae not as above.— 
(1) Proboscis very long . . . . Pangonia. 
(2) Proboscis short. Resting position with 
wings flat, separated . . . . Tabanus. 
(3) Resting position with wings nearly 
parallel with the sides of the body. 
Wings usually brown, spotted with 
white . . . . Hcematopota. 
Fig. 388 —Pupa of 
Tabanus x 4. 
Cyrtid^:. —( Acroceridce ). 
Medium-sized or small flies. Head often very small, eyes usually meeting 
in both sexes. Antennce variable, 3-jointed with a terminal style, 
which may be absent. Venation variable, veins often faint. Thorax 
large and round, squamce very large, abdomen very large and round. 
Mouth-parts variable, often rudimentary. 
These very curious flies are easily recognized by their small down- 
bent head, humped thorax, and very large squamae and abdomen, the 
