MITES AND TICKS. 373 
canis, causing ‘‘mange” in dogs. Follicle-mite (Demodex 
Solliculorum), common in the hair follicles of man and domestic 
animals (Fig. 195). Gall-mites (Phytoptids), forming dimples 
and pouches on plants. 
(4 With tracheze. Harvest - mites (7rombidium), whose minute 
hexapod larvee are troublesome parasites in summer on 
’ Fic. 195.—Follicle-mite Fic. 196.—Itch-mite (Sarcopies scabiet) 
(greatly enlarged). (greatly enlarged). 
insects, many mammals, and man. The so-called ‘red 
spider” (Zétvanychus teleartus) spins webs, and lives 
' socially under leaves. Water-mites, e.g. Hydrachna on 
water-beetles, and Azar on gills of fresh-water mussels. 
Beetle-mites (Gamasus), often found on carrion beetles. 
There is a common red mite on the shore-rocks, known as 
Molgus (Bdella) littoralis. 
Ticks (Ixodidee, etc.) are the largest Acarina. They show a movable 
“‘capitulum ” bearing serrated cutting chelicerze and strong four-jointed 
pedipalps. They are responsible for spreading the germs of some 
diseases affecting man and beast, eg. human ‘‘tick-fever” on the 
