38 PARASITOLOGY. 



Hematopinus Piliferus (Pilus — a hair). 



Animal Infested. — This is the blood-sucking louse 

 of the dog. 



Description. — Its head is short, almost as long as 

 broad. The antennae and legs are short and the 

 abdomen is large and oval in shape. 



Hematopinus Stenopsis (Stenos — narrow). 

 Animals Infested. — Goats and sheep. 

 Description. — The head is long and narrow; thorax 

 short ; abdomen long. 



Trichodectes (Trix— a hair; dectos— biter). 



The species of this genus are small and light in 

 color. The mouth parts are located on the under 

 side of the head. The mandibles are strong and are 

 arranged for mastication. The head is provided 

 v-ith two simple eyes and two short antennae. The 

 head is as wide as long, and wider than the thorax. 

 The abdomen is globular in shape and divided into 

 nine segments. Its food consists principally of epi- 

 dermis. 



Trichodectes Pilosus (Pilos— a hair). 



Animals Infested. — The horse, the ass and the 

 mule. 



Description. — The head is rounded in front ; the 

 antennae are inserted well back and are composed 

 of three articles each. The abdomen is oval and 

 tapers posteriorly. 



Trichodectes Scalaris (Scalaris — to climb — a ladder). 



Animals hifested. — Cattle. 



Description.— This, species is very common. Its 



