76 



PARASITES OF THE DOMESTIC ANIMALS 



Pediculosis of the Sheep 



This animal has one suctorial louse, — Linognathus ■pedalis, and one 

 biting; louse, — Trichoiiedes sphwrocephalus. 



1. Linognathus pedalis (Hsematopinus pedalis). Pediculidge (p. 70). 

 — Has the same general shape as the short-nosed ox louse, but is 

 somewhat more slender. It is also much lighter in color, giving it a 

 somewhat immature appearance (Fig. 43). 



Fig. 4.3. — Hsematopinus pedalis: a, adult female; b, ventral view of terminal seg- 

 ments of same; c, terminal segments of male; d, egg (after 0.sborn, Bui. No. .5, Bu- 

 reau of Entomology, U. S. Dept. of Agr.). 



This species is rare. It is said to occur only where the hair is short 

 upon the legs and feet, especially about the dew-claws. It is from this 

 location that it gets its common name, "sheep-foot-louse." 



2. Trichodectes sphaerocephalus. Philopteridae (p. -71). — Head 

 broad as long, giving the rounded appearance from which the specific 

 name is derived. The abdomen is elliptical, each segment having a 

 median band which is somewhat rounded upon its anterior border. 

 The general color is white (Fig. 44). Of rather rare occurrence. 



The common so-called "louse" of sheep is not a true louse, but the 

 degenerate fly Melophagus ovinus, described elsewhere under the par- 



