ORDER DIPTERA: THE BRACHYCERA 135 



veins are forked, so that there are two submarginal and 

 five posterior cells. The squamae are large. 



The eggs are laid in shapely masses (Fig. 39) on leaves 

 and stems of plants growing in marshy ground or over- 

 hanging water. The larvae live in wet earth, rotting vegeta- 

 tion, or in water, and are carnivorous ; they are cylindrical 

 in form, pointed at both ends, and have several prominent 

 fleshy rings, or bands of pseudopods on the body. The 

 pupa is much like a Lepidopterous pupa. According to 

 Williston the whole term of development, embryonic and 

 post-embryonic, occupies about eleven months. 



The males of Tabanidcs are said to live on the juices 

 of plants, but the females (of most, if not of all of them) 

 are extremely blood-thirsty. Though they attack man 

 freely, they do not — at any rate in most places — afflict him 

 grievously as they do domestic animals ; nor do they come 

 much into dwelling-houses, nor are they known to transmit 

 the infection of any specific disease of man, though they 

 have been shown to transmit the surra trypanosome in 

 India, and other pathogenic trypanosomes of domestic 

 animals in Africa. The possibility of their infective agency 

 in the case of man should, however, be always borne in mind. 

 The family is a large one, about 1600 species having 

 already been described, and is represented in all parts of 

 the world and at all altitudes. In the Pamirs, in 1S95, a 

 species of Tabanus was fairly abundant at a height of 

 not less than 15,000 feet — on the grazing-grounds of Ovis 

 poll. 



The Tabanidce are grouped in two subfamilies, namely : 

 (i) Tabanince, in which there are no ocelli and no spurs on 

 the hind tibise ; and (2) Pangonince, in which there are spurs 

 (though sometimes they are very inconspicuous) on . the 

 hind tibiae, and ocelli are usually present. 



Of the numerous genera of Tabanidae the four most 

 iniportant are (i) Tabanus {sensu latiore), Fig. 40, in which 

 the first 2 antennal segments are short, and the 3rd is 

 angulated or spurred at its base, and is composed of 5 sub- 

 segments ; (2) Hcematopota (Figs. 41, 42), in which the 2nd 

 antennal segment is short, and the 3rd, which is composed 

 of 4 (occasionally 3) subsegments, is not angulated or spurred 



