98 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



V( L. XXVIII. 



Fn. IS.-, 



-(.'NEMI DOCOPTES MUTAXS, 

 KEMALE. 



incessant scratching, which only serves to spread the infection and 



increase the inflsunmation. Chnuiliness is the best preventive. The 



l)est, r(Mnedy is the use of an ointment con- 

 tainino- sulphur. If the ati'ected parts are 

 freely bathed in hot water and soapsuds 

 the seal}' portions of the skin will be re- 

 moved, and then the ointment can be ap- 

 plied with a certainty of reaching- the 

 mites. The application should be re- 

 peated two or three times, each a few days 

 apart, in order to kill any mites that may 

 have hatched since the first application. 

 All underclothes and bedding should be 

 washed in boiling-hot water. The Norwe- 

 gian itch mite is S. scahe!-cruM</sa^; it pro- 

 duces a coarse leprous crust infested on 

 the inner surface with myriads of the 

 mites. It is much less common than the 

 other species. 

 Nearly all of the domestic animals may harbor a species of Sarmptj^s 



peculiar to them. The more com- 

 mon are those of the hog, horse, 



and sheep. They work like the 



human species, and are amenal)le 



to the same treatment, or that 



used for sheep-scab. 



The species of the genus Pso- 



'/vyy>/'r.shave piercing mandibles, and 



do not burrow. One species, 1\ 



coiinnunis var. ovj/.s, is the cause of 



sheep-scab, a serious disease of 



this animal throughout the world. 



The fleece of scal)by sheep presents 



a rough appearance, the wool in 



places being stuck together in 



greasy masses. The mites are most 



abundant ai'ound the edges of an 



infested patch, and increase very 



rapidly. The eggs hatch in two or 



three days, and in fifteen davs they 



become mature. The female lives 



for several weeks and deposits a 



great number of eggs, commonly 



in patches of about twenty each. 



By ru))bing against posts, trees, and fences wool containing mites and 



eggs is removed which may infect healthv sheep rubbing against the 



Fiu. 186. — Otodectes cynotis, femai.k. 



