DIPTERA OE TRUE FLIES. 231 



species very common in Britain, notably Hwmatopoda pluvialis, 

 Ohrysops cceeutiens, Tahanus iovinus, and T. autumnalis. The 

 first named is about half an inch long, whitish-grey, covered 

 with pale dull hairs in the female, dark-grey in tlie male, wings 

 mottled grey. The last two are especially troublesome in the 

 New Forest, where they often tease horses severely. T. bovinus 

 is frequently called the Ox Gad-fly ; and some specimens reach 

 more than an inch in length. In colour the male is dark-brown 

 on the thorax, with five pale stripes, and pale yellowish hair ; 

 abdomen reddish-brown, with a black central line and tip, and 

 with a pale spot in the middle of the posterior borders of the 

 first to the fifth segments ; the under-side of the abdomen 

 orange colour. Eyes green. Wings yellowish-brown, veins 

 yellowish in places. Legs dark-brown, except tibia, which are 

 yellowish-red. The female has a curious coppery sheen over 

 the green eyes, and the abdomen is flatter than in the male. 

 An allied species, called T. sudeticus, is often mistaken for T. 

 bovinus, but can at once be told by the eyes being brown, with 

 a coppery sheen. T. autumnalis is also common : it is much 

 smaller than the above, not much larger than five-sixths of an 

 inch in length ; its general appearance is grey, the thorax having 

 five grey stripes ; the greyish-brown abdomen has three rows of 

 paler grey spots, the central one somewhat triangular. 



Chrysops cceeutiens, or the Blinding Storm-fly, is about half 

 an inch long ; body with black and yellow markings. Eyes 

 golden green, with brilliant purple spots and lines ; wings 

 black, with pale spaces in the male ; transparent, banded with 

 black in the female. It is a most vicious biter. As far as is 

 known, they all feed in their larval state in the ground, and 

 amongst wet decaying vegetation, in sand and soil generally. 

 The larvae are long, cylindrical grubs, yellowish-white in colour, 

 with darker transverse bands ; they are somewhat enlarged in 

 the middle, and change to naked pupae (fig. 127, e) in the soil. 

 The adults come forth much in the same way as the crane-fly : 

 these immobile pupse can be told by the six spines on the 



