H. Kobayashi 
Oral sucker continues into the oesophagus at the posterior median point 
of the former. Oesophagus 1-6 mm. in length; its lumen is narrow and pos¬ 
teriorly it becomes wider and its posterior fourth forms the pharyngeal bulb. 
The pharyngeal bulb has a diameter of 0-45 mm. and it directly divides into 
the caeca. Intestinal caeca broad, running directly and somewhat close to 
the submedian line and terminating posteriorly immediately behind the 
posterior testes, i.e. at the level of posterior two-fifths of the body-length. 
The excretory vesicle lies between the anterior margin of the posterior 
sucker and the shell-gland; posteriorly it becomes a narrow canal which opens 
at the point 1 mm. from the posterior extremity. The whole organ lies posterior 
to Laurer’s canal. Two vessels arise from the vesicle and run anteriorly along 
the inner side of the intestinal caeca. 
The genital pore opens in a slight prominence on the median line, slightly 
posterior to the oral sucker. 
One testis lies behind the other at about the middle of the body in the 
space between the intestinal caeca, partly overlapping the latter. The testes 
are somewhat separated one from the other. Each testis has four or five 
lobes; when four-lobed it is cross-shaped, and inclined at an angle of 45° to 
the longitudinal axis. Each testis is about 1*5—1 *8 mm. in diameter. The 
vesicula seminalis is a broad canal, lying along the median line between the 
anterior testis and the pharyngeal bulb; it has many lateral loops. At the 
anterior part of the pharyngeal bulb it continues into a relatively thick pars 
muscularis which runs directly toward the anterior end and soon narrows, 
forming the pars prostatica. The pars prostatica continues directly into the 
ductus ejaculatorius, which unites with the vagina and thus a very short 
ductus hermaphroditicus is formed. Around the ductus ejaculatorius, the 
vagina and the ductus hermaphroditicus certain muscles are present which 
represent a primitive cirrus-pouch. 
The ovary lies slightly in front of, and to the right of the posterior sucker. 
Its contour is round or ellipsoidal; its diameter is 0-5 mm. The shell-glands 
are attached between the point of bifurcation of the intestinal caeca and the 
anterior margin of the posterior sucker. They lie exterior to the intestinal 
caeca, partly overlapping them. Each consists of from 8 to 12 groups. The 
uterus forms several loops between the intestinal caeca and opens into the 
vagina at the level of the ductus ejaculatorius. The egg is ellipsoid; its size is 
0-12 mm. x 0-06 mm. The shell is not thick, and is operculated. 
II. AVIAN TREMATODES. 
(11) Prosthogonimus japonicus Braun. 
One specimen was collected by O. Takagi, in a hen’s egg, at Ibaraki 
Prefecture, 1915. Body 4 mm. in length by 2 mm. in width. 
