H. Kobayashi 383 
body down to the posterior end and terminate at the blind end, being turned 
slightly mesially. 
The excretory pore is situated at the posterior end. The vesicle is Y- 
shaped, the stem occupying the posterior fifth of the body length and bifur¬ 
cating near the posterior margin of the receptaculum seminis. The two arms 
run forward, parallel with each other, along the submedian line against the 
ventral side of the loops of the uterus, and near the anterior part of the 
intestinal caeca, they pass over the intestine, where the vesicula becomes 
continuous with the collecting vessel. 
The testes are symmetrically disposed in the hindmost quarter of the 
body, each lying close to the corresponding intestinal caecum. They are of 
an irregular, slightly lobate form, with a diameter of about 0*5-07 mm. The 
vasa efferentia arise each from the inner side of the testis, and run antero- 
medially; at the anterior margin of the ventral sucker they unite into one 
tube and form the vesicula seminalis. The vesicula seminalis is spindle-shaped, 
being 0*6 mm. in length. It turns ventrally and is continuous with a short 
pars prostatica. The prostate glands lie on the ventral side of the vesicula 
seminalis and around the pars prostatica. The pars prostatica continues 
directly into the ductus ejaculatorius. 
The ovary is situated on the median line, at the same level or slightly 
anterior to the testes. It is composed of numerous lobes and the whole organ 
presents a broad triangular shape, with a width of 0*8 mm. The oviduct arises 
from the dorsal surface of the ovary. The shell-glands are numerous, and lie 
in the antero-dorsal region of the ovary. The receptaculum seminis is an 
ellipsoid sac which lies posterior to the ovary; its diameter is 0*3-05 mm. 
The Laurer’s canal, after making two or three turns, ends blindly in the dorsal 
parenchyma. The wall of the distal part of the canal has a peculiar vesicular 
structure. The vitellaria lie exterior to the intestinal caeca, and extend from 
the anterior extremities of the intestinal caeca to the level of the receptaculum 
seminis. Each of the vitellaria is composed of from nine to twelve clearly 
differentiated ascini. The yolk ducts run in a mesial direction from near the 
posterior end of the vitellaria and unite at the postero-dorsal margin of the 
ovary. The convoluted loops of the uterus occupy the entire region circum¬ 
scribed by intestinal caeca laterally, and the testes and the ovary posteriorly. 
The vagina runs ventrally, parallel to the ductus ejaculatorius, and opens 
directly into the latter. The eggs (0*026-0*033 mm. x 0*013-0*016 mm.) are 
provided with a clearly visible lid; those contained in the distal part of the 
uterus containing well developed miracidia. 
