12 



out by Girschiier ('Berliner Entomologische Zeitschrift,' Bd. xxxi. 

 (1887), p. 156) " possess probabl)- the finest eyes of all insects." After 

 death, lio\vc\er, the colour of the e}-es rapidly changes to a dull brown 

 or brownish-black, until scarcely a trace of the markings remains.* 



In front of the eyes project conspicuously the three-jointed 

 antenna;, and below the head in all the British forms depends vertically 

 the fleshy proboscis, or lower lip, which encloses the piercing mouth 

 parts. The palpi, which lie one on each side of the proboscis, are 

 swollen and flesh\-, and differ in shape in the two sexes. The body 

 is clothed with short hair and totally devoid of the large bristles 

 known as macroch;vt:v.'. 



In the coloration as in the shape of the bod\- horse-flies throughout 

 the world .show remarkably little variation, and the British species are 

 consequently ver\- similar in appearance to many of those belonging 

 to the same genera found in Central Africa, India and elsewhere. 

 Some shade of brown or black is the most frequent hue, though the 

 abdomen is often lighter or exhibits lighter markings. The wings, 

 which, when the insect is at rest, diverge at the tips or are some- 

 what tectiform (sloping like the roof of a house), have in the case of 

 HiCinatopota and Chrysops characreristic markings, which are well 

 shown in the plates. 



Horse-flies maybe met with throughout the summer in fields, open 

 spaces in woods, or by country roadsides. The edges of woods are 

 favourite haunts of certain species, and when resting in such a place 

 on a hot day one may frequently notice a Hccmatopota or two or a 

 specimen of one of the smaller species of Trt^^MWJ crawling with much 

 deliberation over one's coat and making preliminar\' investigations with 

 its proboscis. The females alone suck blood ; the males of certain 

 species may occasionally be met with on flowers or sometimes hovering 

 in the air. The species of Hiematopota and Chrysops, and the smaller 

 species of yV/^Jwwi' are remarkable for the quietness with which they 

 alight on their victims, the sharp prick of the bite being often the 

 first intimation of the presence of the fly. The larger species of 

 Tabauns betray their approach hy their deep luun. When once the 

 operation of sucking blood has commenced, horse-flies, like other 



* In the plates to this work the eyes are shown as seen in dried specimens, from which 



tlie drawings had perforce to lie prepared ; but so far as possible the natural colour and 



markings are indicated in the notes on each sixcies. 



