PARASITOLOGY. 71 



Animals Infested. — The tick is found in the hens' 

 nests and in the litter. They attack the birds mostly 

 at night. They drive the hens from their nests and 

 cause death of the host. They may be found on larger 

 animals. It transmits the spirochetae gallinarum pro- 

 ducing spirochetosis of fowls in Africa and Europe. 

 Ornithodoros Megnini CMegnin). 



Sy7io7iyiHs. — Spinose tick; ear tick; spider tick; 

 Rhyncoprium Spinosum. 



History. — Found in the South and middle West. 



Description. — The fem.ale, when eng^orged with 

 blood, is about the size of a castor bean. The body 

 is oval in shape, with the transverse diameter of the 

 anterior third greater than that of the posterior third. 

 Its cuticular surface is covered with spines, from 

 which it gets its name, — "spinose tick." The head 

 parts are prominent; the hypostome not provided 

 with denticles in the larval stage. The palpi are 

 round in shape, and long. Its color varies from 

 brown to violet. A specimen, two-thirds engorged 

 with blood, taken from a steer, moulted once, and 

 lived from Feb. 10. 1906, to July 8, 1907. 



Ayiimals Infested. — It infests the ears of horses, 

 cattle and other animals. 



Condition Produced. — They attach themselves to 

 the skin lining the conchi, and also invade the audi- 

 tory meatus. This causes miuch irritation; the animal 

 shakes his head and shows other signs of nervous 

 disorder. It is reported to have caused death. 



Treatment. — Oil, or any antiseptic solution of suffi- 

 cient strength to be a parasiticide. Oil coats over, 

 closing the breathing tubes, and asphyxiates the 

 tick. 



