108 DIPTERA. 



By rubbing paroffiii over his hands, neck, and face, 

 Mr. Wood subs«?quently found himself safe from their 

 attacks. 



The insects belonging to the XylojpJiafjidoe are ex- 

 tremely rare and few ; the larvie, as the name of the 

 family implies, live in decayed wood. 



The Asilidoe are the most powerful and generally the 

 largest of the Diptera ; they are carnivorous in their 

 habits, feeding on other insects, and may sometimes be 

 seen flying away with some unlucky bee or beetle in the 

 mouth. Asilus crahroniformis (Plate IV., Fig. 11), is 

 a large conspicuous insect, marked yellow and black, 

 which gives it a wasp-like appearance ; it is generally 

 distributed. 



The flies of the family Leptidw may be often seen in 

 hedges and wooJs ; one very common species may be 

 found upon the trunks of trees or posts near the 

 water-side ; this is the Leptis scolopacea, the Oak-Hy of 

 the angler, sometimes called the Downhill-fly or Down- 

 looker, from the habit the insect has of immediately 

 turning its head downwards after settling on a tree. 

 It is known to the fly-fisherman also by the name of 

 the Woodcock-fly, the colour bearing some resemblance 

 to that of this bird. The small feathers of the wood- 

 cock or grouse are used in making the artificial liackle- 

 flies. A fly of the same family, and of somewhat similar 

 appearance, is the Atherlx Ibis ; I have seen these fiies 

 congregating in thousands on rails across rivers, brood- 

 ing over a mass of eggs, which they attach to boughs or 

 other objects overhanging streams. The flies die soon 

 after laying their eggs, others come and do the same, 

 till large masses are fornif^d as large as a man's fist. 



