PARASITOLOGY. 73 



Margarapus Annulatus (Annulus — a ring). 



Synonyms. — Boophilus Bovis ; Boophilus Annula- 

 tus; fever tick; Texas fever tick; Ixodes Bovis. 



History. — Found in southern part of United States 

 and in southern Europe. 



Animal Infested. — The ox. 



Description. — The engorged female is about the 

 size of the castor bean, has a constriction in the mid- 

 dle of the lateral sides, with two longitudinal depres- 

 sions anterior to, and three posterior to this con- 

 striction, on both dorsal and ventral surfaces. The 

 legs are not strong, and are located on the ante- 

 rior half of the body. The head is not prominent ; 

 it is provided with mandibles, palpi and hypostome, 

 and the latter is furnished with eight rows of denti- 

 cles. The dorsal shield is small and brownish red 

 in color. The surface of the parasite is often marked 

 with delicate yellowish white wavy lines. The ex- 

 tremity of each leg is provided with a pulvillum, two 

 booklets and a globe shaped apparatus. Breathing 

 is by means of a trachea located on either side pos- 

 terior to the last pair of legs, and covered by a per- 

 forated scale called a Stigmen. The male does not 

 become engorged with blood, but remains flat. Its 

 dorsal surface is a brownish red color. 



Life History. — The engorged female drops to the 

 ground, seeks a secluded place, as under some ob- 

 ject, and begins ovulation (laying eggs) in from 

 three to five days. This period lasts about two 

 weeks. During the period of ovulation the female 

 scarcely moves. The eggs are ovoid in shape and 

 brown in color, and are covered with a varnish-like 

 substance. The eggs are pushed out from the ante- 



