No. 2.] STRUCTURE OF TWO FISH TAPEWORMS. 365 



portion of the ovaries, then turns upward and spreads out in a 

 broad sheet, close to the longitudinal muscles above the testes. 

 Lateral outpocketings are formed as the proglottis becomes 

 more mature, and these branches grow larger until the uterus 

 in the posterior proglottids nearly fills the entire space within 

 the dermo-muscular sac (PI. XVI, Fig. 27, tit^j. 



The ova escape by a cleft in the mid-dorsal wall of the pro- 

 glottids. The formation of the cleft is very gradual and seems 

 to result from a gradual thinning of the dermo-muscular sac at 

 that place. 



In the relations of glands and ducts P. filicollis and P . mnblo- 

 plitis are remarkably similar. 



