PARASITOLOGY. 45 
the whitewash. The litter and straw should be 
removed from the nests and burned, and the nests 
should be disinfected and new straw provided. Be- 
fore refilling with straw, an inch of slaked lime should 
be placed in the bottom. 
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Fig. 14. Fig. 15, Fig. 16. 
Fig. 14.—Goniocotes hologaster, a louse (from a hen), ventral 
view; a, mouth parts; b, antennae; c, hooklets on free extremity 
of leg. The small mark to the right indicates the natural size. 
Fig. 15.—Lipeurus baculus, from the pigeon. Letters indicate 
rame parts as in Fig. 14. 
Fig. 16.—Sarcoptes mutans, variety gallinae, the scab parasite 
producing scaly legs in the hen. a, the mouth parts with which it 
wounds the skin and causes serum to exude; b, the short legs; c, 
the small dot indicates its natural size. 
ARACHNIDA. 
The parasites belonging to this class are not in- 
sects,—the head, thorax and abdomen are not dis- 
tinct, and the head is not provided with antennae. 
ACARINA. 
Under this order we study the following families, 
and sub-families, viz: 
