550 © REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
In sections made in the vicinity of the reproductive aperture, back of 
the posterior fourth of the body, the cuticle was found to consist of two 
layers (Fig. 20, e, ec). The outer or epidermal layer appears to be 
sloughing off from the inner, uniform cuticular layer. Within the 
cuticle is a very thin layer of fine longitudinal fibers. This is sue- 
ceeded by a thick granulo-fibrous layer, which contains numerous 
granules and nuclear bodies, which latter stain deeply in carmine. 
There are also, especially in the older specimens, small clusters of lon- 
gitudinal muscular fibers in this layer (Fig. 16,7). The inner portion 
of this layer is somewhat open or areolar. The water vascular system 
consists of an indefinite number of vessels not clearly defined and of 
various sizes, which, in the posterior part of the body, in the vicinity 
of the reproductive aperture, lie in the inner portion of the subcuta- 
neous granulo- fibrous layer (Fig. 16, w). This characteristic branching 
of the water-vascular system appears to be identical with that observed 
by G. R. Wagener (Natuurk. Verh. Haarlem, x11, 96; Tab. vu, 2). 
Next within the granulo-fibrous layer is a layer of longitudinal mus- | 
cular fibers (Figs. 16, 17, 18, 20, Im). This does not constitute an 
unbroken layer, but consists of numerous clusters of longitudinal fibers 
which lie in the midst of the connective tissue and surround the cen- 
tral space. The latter contains the genital organs. A terminal vore 
leading mto a short duct with thick walls was observed in transverse 
sections through the posterior end of a small specimen. The duct 
enters posteriorly from near one margin and not from the extreme tip, 
and continues anteriorly to the posterior vitelline gland. The same 
was observed in transverse sections of larger specimens, where it 
appeared first in the posterior sections as a pore entering one of the 
margins, and was soon seen, in succeeding anterior sections, toward 
the middle of the sections as an elongated opening with strong walls of 
connective tissue of irregular thickness. In the smaller specimens 
strong connective fibers run from the anterior end of this cul-de-sae. 
This organ is doubtless the terminal pulsating organ common to larval 
cestods. 
Genital organs.—The testes begin a short distance back of the head. 
In a young specimen they began about the anterior third; in an older 
specimen they began almost immediately behind the head. They con- 
sist of globular masses (testicules) of granular protoplasm in the — 
younger specimens. In the older specimens they are irregular in — 
shape and relatively smalier. The granules are collected into minute 
globular clusters and appear in the sections as circular or oval nests of 
nuclei. The testes extend posteriorly nearly to the reproductive aper- 
ture, which is about the posterior fourth or fifth of the body. 
In front of the genital aperture there is a voluminous tube which, 
after making numerous convolutions, communicates with the cirrus bulb. 
This tube is evidently the vas deferens (vide Figs. 13, 14, 15, 16). In 
sections of a large specimen it was seen to contain numerous masses 
