J 28 ^- GOTO. 



canal swollen by the sperm mass which it contains ; and is thercfoi-e 

 subject to considerable variations in jsize. 



In Epihilella the position of the external opeaing of the vagina 

 is very similar to that in Tristoinum: in E. Isliikaivae it is only a short 

 distance behind the common genital pore, but in E. omta it is situated 

 about midway between the posterior end of the pharynx and the 

 anterior end of the ovary, a little internally to the left intestinal 

 trunk, and is surrounded by the compact, refractive tissue already men- 

 tioned in describing other genera '(PI. XXVIT, figs. 1, 3, 4, & 6). In E. 

 lahikaiKie the vaginal canal makes numerous windings in its course, 

 and finally opens into the yolk -reservoir ; but in E. omta it is nearly 

 straight, and after a short course opens into the yolk-reservoir as in 

 the other species. In this genus I have not observed any receptaciihim 

 xeminis, but this may possibly be owing to the absence of any sperm 

 mass at the particular time or in the particular specimens I have 

 examined. Yon Linstow'^ does not mention any vagina in Phyl- 

 line Hendorff'ii, but what he describes as the receptaculum seminis is 

 probably nothing else than the proximal end of the vaginal canal, com- 

 parable to the seminal receptacle of Tristomiim. In Phyllonella soleac 

 also, the vagina has not been described; but to judge from the figure of 

 the worm given by Cunningham,^^ I believe it is present likewise 

 in this species. The convoluted dark tube drawn by that writer on the 

 leftside (right side of figure) of the yolk-reservoir in fact represents, 

 in my opinion, the proximal portion of the vaginal canal. 



The wall of the vaginal canal consists in most species of a thin, 

 refractive membrane similar to that of the larger yolk-ducts ; and 

 I have never observed any nuclei in it. In Calicotijle, however, the 



1). V. Linstow— Beitrag zur Anatomie von Phylliue Hendorffii. Arohir f. mik. Anatomic. 

 Bd. 33, 1889, p. 173. 



2). J. T. Cunningham— A Treatise on the Common Sole, 1890. p. 93. 



