F. J. Meggitt 
273 
darkly staining nuclei and has a diameter of 0-0512 mm. It first appears 
about the 6th segment, becomes functional in and persists as a vestiger 
until the 16th. 
The shell-gland (PI. XX, fig. 2) surrounds the vestibule as it passes 
directly dorsal to the yolk-gland. Its edges touch and appear to fuse 
with those of the yolk-gland : this causes it to appear merely an irregular 
proliferation of the latter : it was probably this appearance which caused 
Cohn to overlook its occurrence. The two glands are quite distinct how¬ 
ever in character, for while the yolk-gland is composed of spherical cells 
the cells of the shell-gland are irregular in shape and have a more irregular 
distribution of the nuclei : the gland itself lacks the compactness of 
the yolk-gland. 
The vagina (PI. XX, fig. 4) opens into the extreme end of the genital 
sinus, posteriorly to the cirrus, the opening having a diameter of 
0-0062 mm., and being surrounded by the usual well-developed sphincter 
muscle. The vagina immediately bends sharply anteriorly and then 
runs horizontally past the end of the cirrus sac, nearly to the dorsal 
margin of the proglottis. Bending ventrally again, it opens through a 
constriction into the broad end of an elongated pear-shaped receptaculum 
seminis, situated in the centre of the segment. The receptaculum seminis 
is 0-093 mm. long and 0-0391 mm. wide at its broader end, 0-0207 mm. 
at the other. This latter end (PL XX, fig. 2) curves ventrally and then 
divides into two. The broader branch {ov.d.) continues to curve ventrally 
as far as the ventral border of the proglottis: there it runs anteriorly, 
and slightly towards the cirrus-sac side of the segment, to open into the 
ovary near the anterior margin of the proglottis. 
The narrower branch or vestibule {ves.) runs at first anteriorly, but 
almost immediately doubles back upon itself and runs posteriorly and 
dorsally to pass through the shell-gland near the posterior margin. 
The vitelline duct here opens into it on the ventral surface. This latter 
is a short duct posterior to the shell-gland, joining the vestibule 
and the yolk-gland. After passing through the shell-gland, the vestibule 
curves ventrally and then runs antero-laterally, still on the dorsal side 
of the receptaculum seminis, to the centre of the anterior margin of 
the proglottis. It then bends ventrally at right angles to its former 
course, and expands in the middle line into the uterus {u.). 
My own specimens confirm Cohn’s opinion that this is from the 
beginning a simple sac : there seems to be' no grounds for Magelhaes’ 
statement, “ Les oeufs se developpent a I’interieur de 13 a 15 grosses 
vesicules ou cavites rangees suivant le bord posterieur de I’anneau 
