78 
Parasitic Arthropods 
Notoedres cati (usually known as Sarcoptes minor) is a species 
of itch mites which produce an often fatal disease of cats. The body 
is rounded and it is considerably smaller than Sarcoptes scabiei , 
the female (fig. 61) measuring 215-230^ long and 165- 175^ wide; 
the males 145-150^ by 120-125^. The most important character 
61. Notoedres cati, male and female. After Railliet. 
separating Notoedres from Sarcoptes is the position of the anus, 
which is dorsal instead of terminal. The mite readily transfers 
to man but does not persist, the infestation usually disappearing 
spontaneously in about two weeks. Infested cats are 
very difficult to cure, unless treatment is begun at 
the very inception of the outbreak, and under ordi¬ 
nary circumstances it is better to kill them promptly, 
to avoid spread of the disease to children and others 
who may be exposed. 
Demodecidae 
The Demodecidae are small, elongate, vermiform 
mites which live in the hair follicles of mammals. 
The family characteristics will be brought out in the 
discussion of the species infesting man, Demodex 
folliculorum. 
Demodex folliculorum (fig. 62) is to be found very 
commonly in the hair follicles and sebaceous glands 
of man. It is vermiform in appearance, and with the 
elongate abdomen transversely striated so as to give 
62 . Demodex foiii- it the appearance of segmentation. The female is 380- 
Af tef 11 bi ar! ch ard! 400[A long by 45 ^; the male 300^ by 40^. The three- 
