320 LEWIS HENKY GOUGH. 



The best desci-iptiou of these two species avaiUible hitherto 

 was by Stiles (1893), who also revised the generic diagnosis, 

 basing his revision on the then known data, though evidently 

 not feeling quite sure as to the desirability of leaving both 

 species in one genus. 



In 189G Eailliet described a new species, Stilesia vittata, 

 from the intestines of a dromedary ; he considered this species 

 to be very closely allied to Stilesia globipunct;ita (Riv.), 

 and, perhaps, only to be a variety. 



In 1903 another new species, closely related to Stilesia 

 globipunctata (Riv.), was described by Wolff hiigel, from the 

 bile-ducts of sheep and goats in South and East Africa, as 

 Stilesia hepatic a. 



In 1900 Tenipere briefly refers to Stilesia centripunc- 

 tata and figures its scolex, apparently only quoting from 

 Railliet (1893) and Neumann (1893). 



In 1908 Gough states briefly that Stilesia hepatica^ 

 Wolffhiigel, is usually not double-pored. 



In 1909 Fuhrmann phices Stilesia and Thy sanosonia in 

 a new sub-family, the Thysanosomi nse. 



In 1909 Fuhrmann desci'ibes a new species from Trage- 

 laphus sylvaticus mernensis, collected by Dr. Sjostedt 

 on the Masai steppes, as Stilesia sjcistedti. 



In 1909 Gough gives a full description of the anatomy of 

 Stilesia centripunctata (Rivolta), Avith remarks on 

 Stilesia hepatic a, Wolffhiigel. 



At present, therefore, the genus contains the following five 

 species : 



Stilesia centripunctata (Rivolta), 1874; Stilesia 

 globipunctata (Rivolta), 1874; Stilesia vittata, Railliet, 

 1896; Stilesia hepatica, Wolffhiigel, 1903; Stilesia 

 sjostedti, Fuhrmann, 1909. 



The last four species agree very closely in their anatoni}^ ; 

 the first differs from all the others in several important 

 respects of genetic value. A new genus will therefore have 

 to be proposed for Stilesia centripunctata. 



Stilesia globipunctata (Riv). is the type species of the 



