264 BENEDICT. [Vol. XVI. 



lar band, oval in section (PI. XVI, Fig. 35). This organ in 

 P.filicollis resembles closely that of P. ambloplitis. 



The oviduct is lined by cubical, thickly ciliated cells. Around 

 this layer is a thin stratum of what appear to be muscle ele- 

 ments running transversely ; then comes an epithelial covering, 

 and outside of this are scattered gland cells. The course of 

 the oviduct depends somewhat on the direction of the oocapt, 

 requiring another curve if this organ is directed anteriad ; but 

 in all cases the oviduct passes in slightly curving lines nearly 

 to the posterior margin of the proglottis. Here it may make 

 a coil or two, or bend directly forward again to the center of 

 the inter-ovarial space. The vagina usually enters the oviduct 

 near the posterior margin of the proglottis, although the union 

 is not at exactly the same place in different proglottids. 



The ootype seems to be simply a specialized portion of the 

 oviduct. The muscle layer is a little thicker ; the cilia are very 

 small, or entirely lacking ; and the surrounding gland cells are 

 more numerous. The organ is .0125 mm. long, and for the 

 entire distance is surrounded by the shell gland, which in this 

 form is exceedingly irregular in shape. Around the ootype is 

 a dense portion with a striated appearance, as if composed 

 mainly of cell processes (PI. XVI, Fig. 30, sh.gl.). Long 

 strands extend outward from here, leading to bunches, or 

 masses, of cells of irregular shape. There is, moreover, no 

 similarity in the form of the shell gland in different pro- 

 glottids. 



The vitellaria are found on the lateral margins of the space 

 within the dermo-muscular sac. Each is formed of a loose 

 mass of vesicles, joined to a central longitudinal duct by fine 

 transverse branches (PL XVI, Fig. 27, vt.gl). The central 

 ducts at the base turn directly inward, and meet a little ante- 

 rior to and above the ootype. At their junction a small vitella- 

 rian reservoir is formed of variable size. From this reservoir 

 a narrow duct leads downwards and backwards to a larger 

 spherical reservoir, lying just above the ootype, into which it 

 empties by a very narrow duct (PI. XVI, Fig. 30, vt.r). 



The uterus extends as a delicate walled tube anteriorly from 

 the end of the ootype. It passes forward under the connecting 



