PARASITES OF ANIMALS. 



41 



Figure 33. 



The Cattle-louse (Hcematopinus vituli Denny). Figure 33- 

 In the genus Hcematopinus, which includes a large number 

 of species, the head is obtuse or truncated in front, the middle 

 segments of the abdomen well separated, and the posterior 

 legs much the longest. The eyes are very minute. They are 

 all small and some are minute species. 



H. vituli is brownish, with a pale 

 abdomen, the abdominal segments 

 bearing lateral chitinous pieces, in 

 which the spiracles are situated. The 

 head is elongated with a constriction 

 behind the antennse. It is about j 1 ^ 

 of an inch in length, or a little more. 

 It is parasitic both on cattle and horses, 

 and sometimes becomes very abun- 

 dant. 



Another species (H. eurysternus 

 Denny), also infests both cattle and 

 horses. In this the head, thorax, and feet are horn-colored. 

 The thorax is very broad. The length is about T V of an 

 inch. 



The Hog-louse (Hcematopinus suis Leach). Figure 34. 

 Figure 34. This species is brown, with a white 



abdomen. The spiracles are placed in 

 blackish, horny plates along each 

 side of the abdomen. Length -J of an 

 inch. 



H. stenopsis infests the goat. It is 

 a horn-colored species, with along oval 

 hairy abdomen. 



If. asini Denny is parasitic on the 

 ass. 



H. piliferus Denny lives upon the dog. It is uniformly 

 horn-colored. The body is slender and covered with pale 

 hairs. Length $ of an inch. 



Figure 33. Cattle-louse (Hcematopinus vituli Denny), much enlarged. From 

 American Naturalist. 



Figure 34. Hog-louse (H. suis Leach), much enlarged. From Cuvier. 

 6 



