LICE OF DOMESTIC ANIMALS. 



103 



in their natural order, beginning with the highest form and 

 that which is nearest allied to Pediculus. 



The common barn-yard fowl is infested by a louse that we 

 have called Goniocotcs Burnettii (Fig. 121), in honor of the late 

 Dr. W. I. Burnett, a young and 

 talented naturalist and physiolo- 

 gist, who paid more attention than 

 any one else in this country to the 

 study of these parasites, and made 

 a large collection of them, now in 

 the museum of the Boston Society 

 of Natural History. It differs from 

 the G. hologaster of Europe, which 

 lives on the same bird, in the short 

 second joint of the antenna, which 

 are also stouter; and in the long 

 head, the clypeus being much 

 longer and more acutely rounded ; 

 while the head is less hollowed out 121. Louse of Domestic Fowl, 

 at the insertion of the antennae. The abdomen is oval, and 

 one-half as wide as long, with transverse, broad, irregular bands 

 along the edges of the segments. The mandibles are short and 

 straight, two toothed. The body is slightly yellowish, and 

 variously streaked and banded with pitchy black. The duck is 

 infested by a remarkably slender form (Fig. 122, Phil- 

 opterus squalidus). Figure 123 represents the louse 

 of the cat, and another species (Fig. 124) of the same 

 genus (Trichodes) lives upon the goat. 



The most degraded genus is Gyropus. Mr. C. Cook 

 has found Gyropus ovalis of Europe abundant on 

 the Guinea pig. A species is also found on the por- 

 poise ; an interesting fact, as this is the only insect 

 we know of that lives parasitically on any marine 

 animal. 



The genus Goniodes (Fig. 125, G. stylifer, the tur- 

 122. Duck ]j e y louse) is of great interest from a morphological 

 Louse - and developmental point of view, as the antenna? are 

 described and figured by Denny as being " in the males cheli- 

 form (Fig. 126, a, male ; b, female) ; the first joint being very 

 large and thick, the third considerably smaller, recurved towards 

 the first, and forming a claw, the fourth and fifth very small, 



