10 
siderable, the malady should be left to take its course, and those 
which present the gravest symptoms should be sent to the 
shambles.” 
Melophagus ovinus. —Fly, magnified, with line showing natural length; 
puparium, magnified (showing incrustation), also natural size. 
The Sheep Spider Fly and the Horse Forest Fly (mentioned 
further on) differ from all the other kinds of flies mentioned in 
these pages in their methods of propagation and habits. They only 
live actively in fly state, and they multiply, not by egg-laying or by 
deposit of ordinary maggots, but by deposit (or laying) of maggots 
in the very act of altering into puparia, or pupa-cases, commonly 
known as chrysalids, from which, in due time, the fly comes out. 
With regard to the name of Sheep Tick, which is so commonly 
bestowed on this sheep pest that it may be said to be now the 
established appellation, it should be observed that it is in reality 
not a Tick at all. The difference may be easily told by noticing 
that the true Tick possesses eight legs, excepting in its earliest 
(that is, its larval) state, when it has only six ; and also Ticks have 
no division between the fore body and abdomen. 
The so-called “ Sheep Ticks” (Melophagus ovinus) are wingless, 
about a quarter of an inch long, flattisli in shape, leathery in 
texture and bristly, especially on the abdomen and legs. The 
colour brownish, varying in tint on different parts of the body and 
legs, and more or less tinged with grey on the abdomen. The head 
is squarish, rather wider than the thorax, in which it is partially 
sunk, and is furnished with a tubular proboscis, protected externally 
by two flat elongated bristly pieces. The eyes very small; ocelli 
or simple eyes none; the horns (antenna) very short, sunk in pits, 
and wart-shaped at the ends. 
The thorax (or fore body), as seen from above, is square, and is 
without wings. The abdomen is much contracted at the base, and 
