102 



CERTAIN PARASITIC INSECTS. 



119. Louse of Cow. 



maxillae, or labium. Figure 116 represents the mouth parts 

 of the same insect a little farther advanced, with the jaws and 

 labium elongated and closely folded together. Figure 117 repre- 

 sents the same still farther advanced; the mandibles (mad) are 

 sharp, and resemble the jaws of the 

 Mallophaga; and the maxillae (jnax l j 

 and labium (max 2 ) are still large, while 

 afterwards the labium becomes nearly 

 obsolete. Figure 118 represents a front 

 view of the mouth parts of a bird louse, 

 Goniodes; Ib, is the upper lip, or 

 labrum, lying under the clypeus; mad, 

 the mandibles; max, the maxillae; Z, 

 the lyre- formed piece; and pi, the 

 "plate." 



We will now describe some of the 

 common species of lice found on a few 

 of our domestic animals, and the mal- 

 lophagous parasites occurring on cer- 

 tain mammals and birds. The family 

 Pediculina, or true lice, is higher than the bird lice, their mouth 

 parts, as well as the structure of the head, resembling the true 

 Hemiptera, especially the bed bug. The clypeus, or front of the 

 head, is much smaller than in the bird lice, the latter retaining 

 the enlarged forehead of the embryo, it 

 being in some species half as large as 

 the rest of the head. 



All of our domestic mammals and 

 birds are plagued by one or more species 

 of lice. Figure 119 represents the Hae- 

 matopinus vituli, which is brownish in 

 color. As the specimen figured came 

 from the Burnett collection of the Bos- 

 ton Society of Natural History, together 

 with those of the goat louse, the louse 

 of the common fowl, and of the cat, 

 they are undoubtedly naturalized here. 12 - Louse of Ho - 

 Quite a different species is the louse of the hog (H. suis, Fig. 

 120). 



The remaining parasites belong to the skin-biting lice, or 

 Mallophaga, and I will speak of the several genera referred to 



