ECTOPAEASIÏIC TEEMATODES. 267 



to the students wlio can command fresh specimens of the present 

 species, since these cells will, in my opinion, form, from their 

 gigantic size and the stoutness of their processes, especially fit 

 objects for the application of the methylene blue or Golgi 

 method. For instance, the fusiform cell on the left side of the 

 anterior chitiuous piece shown in fig. 5, measures 74 /-< across. 

 Besides the cells shown in fig. 5, I have observed a few similar 

 cells in their vicinity, bat they seemed to me inconstant both 

 in position and number. 



The descriptions of the genital organs given by van Beneden 

 ['61] and Cunningham ['90] require some comments and correc- 

 tions. The general arrangement of these organs are very similar 

 to that of the allied genus Epibdella, but presents some peculiar 

 features. There are two genital openings, the common genital 

 pore and the vaginal pore (fig. 3), the former being situated on 

 the left side of the body close to the lateral margin, and direct- 

 ly behind the hind end of the anterior membranous portion of 

 the body, and the latter lying slightly internal to the former 

 and at a short distance behind it. The vaginal canal proceeds 

 obliquely backward and opens into the yolk reservoir just as in 

 Tristomum and Epibdella, and bears no seminal receptacle on its 

 course. It has been observed by van Beneden ['61, p. 34] and 

 designated in his figure ['61, pi. Ill, fig. 1] as a " glande 

 s'ouvrant à côté de l'orifice des organes sexuels," of the connec- 

 tion and function of which, however, the author was not quite 

 sure. Cunningham ['90] also describes a " vesicula seminalis " 

 in connection with the vas deferens ; but it can not be anything 

 else than the vagina. Again, van Beneden speaks of " deux 

 vésicules séminales " ['61, p. 29]. Here, however, I must point 

 out the discrepancy of terminology between his text and figure. 



