F. D. Weidman 
275 
thinner portions of the uterus were due to the internal pressure of the 
ova. It would appear from the findings here that the sacs are deve¬ 
lopmental features, and of hereditary rather than acquired nature. 
Additional weight is lent to this view by the occurrence of one or 
two places of thinning which are not distended. Spermatozoa were 
not found in this tube except close to the ootype. 
The vitellaria consist of two roughly triangular structures occupying 
the posterior two-thirds of the worm; the broader side of each triangle 
is convex and follows the body margin; the other two sides are concave, 
and their angle of junction is directed toward the ovary. The vitellaria 
consist of very small sparse follicles containing minute quantities of 
pink granules; as already stated above, each mass is pierced bv the 
caecum. The courses of the ducts are not surely made out either in 
their transverse or longitudinal portions. In the specimen here studied 
a vitelline reservoir is easily made out close to the shell gland and to 
the right of the same, but a communication with the genital tube on 
the one hand, or with the vitellaria on the other, could not be established. 
Other writers disagree upon the arrangement of the terminal vitelline 
apparatus; Otto states that two transverse ducts form a common longi¬ 
tudinal one which enlarges posteriorly to reservoir proportions, that it 
then narrows markedly and unites with the genital tube shortly posterior 
to the point where it is joined by Laurer’s canal; Fischoeder describes 
the vitellaria as emptying into a paired, distinct reservoir, but does 
not state the manner of its communication with the genital tube. The 
extent of the vitellaria farther forwards is a little different in this 
specimen from what has been described by other authors. Otto limits 
the vitellaria to the posterior third, and other writers to the posterior 
half. The vitellaria were especially sparse in the specimen cut longi¬ 
tudinally. The obscurity of these ducts is probably explained by the 
immaturity of the specimens. 
The ova teased from the uterus of the largest specimen are oval, 
not operculated, and measure 0-13—0T5 x 0-085—0-09 mm. 
The Muscular System. 
Apart from the features which have already been noted, the suckers 
do not vary from the plan usually found in other Amphistomidae. The 
subcuticular musculature varies in one respect, i.e. the bundles occurring 
“over the venter are much more robust than those of the margin and 
dorsum. The increase in their size here is so marked as to seem scarcely 
