322 LEWIS HENRY GOUGH. 



(Riv.), vittata, Railliet, liepatica, Wolfihiigel, and 

 sjostedti, Fulirinaiin, remain. For T^nia centripunc- 

 tata, Rivolta, a new genus must be erected, for which I 

 propose the name Avitellina (to denote the absence of a 

 vitelline gland). 



Avitellina, no v. gen . Type species, Avitellina centri- 

 pun ctata (Rivolta). Head with four suckers, but without 

 hooks. Strobila thin and narrow. Segments broader than long, 

 flat in the proximal portion of the strobila, nearly cylindrical 

 in the posterior portion. Genital pores irregularly alternate. 

 Four distinct sets of testicles in each segment, one right and 

 one left of each longitudinal canal, but no testicles in the 

 middle field. Ovarium nearer the pore side; no vitelline 

 gland, no shell gland ; a single uterus. Eggs finally enclosed 

 in egg-pouches (paruterine organ). The genital canals pass 

 dorsally of the nerve and longitudinal canals. Eggs with two 

 envelopes. Habitat : Intestine of sheep, Africa, Italy. 



The genera and the hitherto described species of Stilesia 

 and Avitellina can be recognised by the following key : 



(1) Uterus single; a single paruterine organ; testicles in 

 four groups; tlie genital canals pass dorsally of the dorsal 

 canal. Avitellina, 4. 



Uterus double; two paruterine organs; testicles in two 

 groups; the genital canals pass ventrally of the dorsal cannl. 



Stilesia, 2. 



(2) Testicles all lateral to the ventral canal. 3. 

 Testicles mostly median or dorsal to the ventral canal. 



St. liepatica, Wolff hiigel. 



(3) The vas deferens forms a dense packet of convolutions 

 (functi(jnally a vesicula seminalis) between nerve and ventral 

 canal Ijefore reaching the cirrus pouch; inhabits the small 

 intestines of the dromedary. St. vittata, Kailliet. 



I'lie vas deferens forms at the most three or four loose 

 convolutions between the nerve and the ventral canal before 

 reaching the cirrus pouch ; inhabits the intestines of sheep 

 and goat. St. globipunctata (Rivolta). 



(4) The vas deferens runs its entire length dorsal to the 



