62 



OS BORA'. 



[Vol. II. 



thin-walled homologue of the oral sucker. This narrows rapidly 

 posteriorly and leads into a pharynx, oval in outline, and com- 

 posed of muscular tissue and cuticularized on its outer surface. 

 Posterior to this chamber there is, as in Aspidogaster {Stafford, 

 Fig. i) and Stichocotyle, Nickerson ('94), a very short oesopha- 

 gus, whose wall is cuticularized and not glandular, followed 

 immediately by a single, rather large tube, the intestine. This 

 runs down the body to near the posterior end (section No. d>^ of 

 Fig. i), where it ends on the same level as the opening of the 



Fig. 6. — Transverse section of P. anodontne, serial No. 54, passing through the ovary. The 

 right side of the figure is the left of the animal (camera lucida). 



excretory system. This tube has a uniform diameter (see Int., 

 Figs. 5, 6), and is lined with tall glandular cells, which are, many 

 of them, peculiarly vacuolated at the outer end (i.e., next the sur- 

 face of the membrane), as noted by Nickerson in Stichocotyle. 

 The excretory system was only recognized in sections, and, 

 as to its terminal portions, its minor divisions, and their rela- 

 tions to the inter-spaces of the parenchyma, must be studied 

 upon living specimens. The excretory pore is clearly visible 

 in sections and in surface views of total preparations. It is 

 located in section No. 83, and it is a single opening, and not 

 double, as reported for Aspidogaster by Stafford. The sections 

 on which this conclusion rests are not shown in this article, but 

 will be given in connection with my later paper. Two enlarged 

 terminal collecting excretory vesicles are seen meeting beneath 

 the surface pore in horizontal sections. They can be traced 

 forwards on either side, but ultimately they are lost in the par- 

 enchyma. These points are indicated in Fig. i. 



