S. Yoshida 
587 
by parenchymatous tissue in which the vas deferens and cirrus are 
embedded. The vas deferens in the cirrus pouch passes straight toward 
the opening of pouch, and becomes a cirrus, which is protrusive. In 
the anterior segments, the vas deferens coils somewhat in the basal 
part of the pouch. Leaving the cirrus pouch, the vas deferens runs 
inward to the median line of the segment taking a slightly winding 
course, nearly parallel to the vagina (PI. XXIII, fig. 21, L). The 
further connection to the testes could not be traced. The vas deferens 
measures 0-02 mm. in diameter within the pouch and 0-022 mm. in 
diameter outside it. 
Testes (PI. XXIII, fig. 21, H) numerous, scattered chiefly dorso- 
laterally and a few posterior to female organs; oval in shape, measuring 
0-115 X 0-08 mm. 
Female organs. Vagina (PI. XXIII, fig. 27, F) opens into common 
genital cloaca immediately antero-dorsal to the opening; from its 
orifice it runs inward, then bends backward to unite with the oviduct, 
coils once, and runs forward to open into the shell gland. The transverse 
portion of the vagina is of nearly uniform diameter (0-03 mm.), the 
proximal portion narrows (0-017 mm.); it is lined by a single cell- 
layer and surrounded by a thick cell-layer. 
Ovary (PI. XXIII, fig. 21, K) occupies nearly all the median posterior 
ventral half of the segment. The oviduct arises midway along the ovary 
and runs back to unite with the vagina; at its origin is a spherical 
“egg-swallower” with a muscular wall (0-01 mm. in thickness); oviduct 
wall of similar structure to vagina. Egg (ovarian); spherical or oval, 
0-02 X 0-013 mm. with nucleus measuring 0-0115 mm. Shell gland 
(PI. XXIII, fig. 21, SD) situated posterior to the ovary; oval, measuring 
0-1 X 0-065 mm. 
Yolk glands (PI. XXIII, fig. 21, D), numerous, longitudinally arranged 
outside the excretory canals; their main ducts (G) run inward posteriorly 
in the segment, meet in the median line and open into the shell gland 
by a short duct. Uterus (U), lies in the median portion of segment; 
in anterior segments it is only represented by cell groups within which 
a lumen appears that subsequently enlarges, ultimately, in the posterior 
part of the strobila, occupying almost all the median portion of the 
segment. In mature segments the uterus swells out rendering the seg¬ 
ments globose (Text-fig. 3, F). The uterine ovum, with shell, is nearly 
spherical and measures 0-034 mm. 
Affinities. The external features of the scolex, such as the number 
of the hooks, and the bothridium form, are as in the genus Calliohothrinm, 
