6 
SHEEP SCAB. 
by their more rounded form of body, the smaller fourth pair 
of legs, which do not have the gossamer threads, the two teat- 
like projections at the extremity of the abdomen, and the large. 
Figure I. — Sheep Scab-Mite {Psoroptcs communis): 1, adult 
female, dorsal view; 2, egg; 3, newly hatched young; 4, jaws, 
which are also shown at 5aa; 5, head and one fore leg, showing 
mouth parts and sucker-like foot; 6, male above, female below, 
in copula. (Copied from AniwM Parasites of Sheep, by Curtice.) 
flesh-colored area on the posterior dorsal part of the body. 
Whenever any considerable number of specimens are taken to- 
gether there will nearly always be a few pairs in copula, as 
