SARCOPTIDA GWRICOIvA : WSTROPHORIN^. 



General habits : Live on detritus in fur of rodents. Listrophorus Gibbo- 

 sus : Lips form pincers ; live on rabbits and hares. L. Mustelcs : On head, 

 neck and shoulders of ferret, etc. L. Leuckarti : Very long ; on field mice, 

 partridges, etc. Myocoptes MuscuUnus : On nose of mouse and rat ; harm- 

 less. 



Common on rodents these are exceptionally found on other 

 mammals, and might be mistaken for psoric acari. They are 

 not known to injure their hosts but merely live among the fur, 

 and feed on detritus. 



Listrophorus Gibbosus. I/ips forming pincers, to seize the 

 hair. Dorsum convex, rounded. Male with long, bifid, flat, 

 posterior projection. Length 0.5 mm. Common on rabbits and 

 hares. 



Listrophorus Mustelcg. Acarus of weasel. The plate of the 

 cephalothorax in two movable pieces. Male notched posteriorly, 

 without caudal projection. Length male 0.4 mm.; female 0.45 

 mm. to 0.5 mm. This has been found on the head and anterior 

 part of the body of the ferret and polecat. 



Listrophorus Lenckarti. Much longer than the above acarus, 

 this has been found by Pagenstecher and-Megnin on field mice, 

 partridges and related birds. 



Myocoptes MuscuUnus (mus mouse, copto I cut). Body small, 

 flat, narrowed in front, with very short rostrum ; third pair of 

 legs in the male and the fourth also in the female enlarged, flat- 

 tened and curved to firmly grasp the hairs. Found on the nose 

 of mouse and rat, and harmless. 



SARCOPTIDA PSORICA. 



Acari of Scabies : Flattened body, symmetrically striated ; legs, two front 

 pairs near the head ; two posterior near back border. Legs bear bell -shaped 

 sucker, posterior ones often long hairs only. Male orifice between two last 

 limbs with chitinous plates, and two lateral suckers to fasten on female. 

 Female orifice just above posterior border. Oviparous : Eggs hatch in one 

 to ten days ; larva, nympha, mature, ovigerous. Fecundity : New genera- 



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