Abdomen long, scarcely broader than the thorax but slightly 

 narrowed behind, almost always longer than the head and thorax 

 (including the scutellum) together, composed of seven segments ; 

 second segment longest and usually broadest, and the following ones 

 gradually diminishing in both the length and width, with anal end 

 usually blunt ; basal part of the abdomen usually bearing conspicuous 

 orange markings which are very different in the two sexes, if the 

 basal markings wanted or present through the side of the abdomen 

 there is almost no different in both the female and male. Genitalia 

 in both sexes small and almost always concealed inside the anal seg- 

 ment. 



This genus is found nearly all over the whole world, but it is 

 not yet recorded from New Zealand. About seventeen species occur 

 in oriental regions, about thirty six in Palaearctic regions, and 

 about thirty five in Aethiopian regions, while about ninty eight have 

 been described from the whole of America, but only one distinct species 

 from Australian regions ; at the present time we know six species in 

 Japan (including Sakhalin and Formosa), one of these has been only 

 recently described from Sakhalin Island by Prof. S. Matsumura, while 

 I have described a distinct new species in this paper. 



The flies almost always occur in the neighbood of water 

 or wet places, and the females annoy cattle and human beings by 

 their perisistent attacks. 



Key for Species. 



I. Abdomen yellowish with black stripes. 



2. Discal cell hyaline; abdomen with four long black stripes 



mlokosiewiczi. Big. 



22. Discal cell hyaline ; abdomen with black bifid stripe on the 

 second segment, often extending to the third or fourth segment 

 dispar, Fab. 



II. Abdomen black, whitish or yellowish at base. 



