270 Hominoocious Arthropods 



kk. Anal opening below. 



I. Pedicel of the suckers jointed; mandibles styliform 



and serrate near the tip Psoroptes Gerv. 



P. communis ovis is the cause of sheep scab. 



II. Pedicel of the suckers not jointed; mandibles 

 chelate. 



m. No suckers on the legs of the females; parasitic 



on birds, including chickens. C. mulans is 



itch mite of chickens. Cnemidocoptes Furst. 



mm. Suckers at least on legs I and II; parasitic on 



mammals, 

 n. Legs very short; in the male the hind pairs 



equal in size; body usually short 



Sarcoptes Latr. 



S. scabiei is the itch mite of man (fig. 56). 



157. Amblyomma, female. After Nuttall 

 and Warburton. 



nn. Legs more slender; in the male the third pair 

 is much larger than the fourth; body more 

 elongate. 



o. Female with suckers on the fourth pair of 

 legs. Species do not burrow in the skin, 

 but produce a scab similar to sheep scab. 

 They occur in the ox, horse, sheep and goat 



Chorioptes Gerv. 



C. symbiotes bovis of the ox has been 

 recorded a few times on man. 

 oo. Female without suckers to the fourth legs, 

 p. Hind part of the male abdomen with two 



lobes. On a few wild animals 



Caparinia Can. 



