Habits and structure of Cotylaspis insignis Leıpy. P11 
wall and the body, in front and on the sides, inwards and backwards 
till it meets the ventral surface of the intestine near its hind end. 
Its relation can be seen in Fig. 7, 9 and 14. It sub-divides the 
animal in front into two parts, the body and the sucker portion, 
Fig. 9, posteriorly this division does not exist as seen in Fig. 10. 
This is different from Aspidogaster where as I understand it the 
diaphragm extends the entire length of the body. Another point in 
which these closely related genera differ is in the position of the 
vitellarian follicles which in Cotylaspis are located beneath the 
diaphragm in the region where it is present while in Aspidogaster 
they are dorsal to it. The diaphragm is formed from the longitudinal 
and oblique muscles coats of the body-wall, as shown in Fig. 14, 
these layers leave the wall of the ventral sucker and continue 
inwards, the same can be seen in Fig. 9. 
The parenchyma muscles are long and often branched, as noted 
* by Nickerson in Stichocotyle, and by STAFFORD in Aspidogaster. They 
are most commonly found in three situations, viz., (a) running across 
from one part of the body-wall to another when these come near 
together, e. g., in the mouth funnel, and in the sides of the body 
between point where the diaphragm joins the side of the body and 
the ventral sucker. (db) From the pharynx to the body-wall long 
fibers stretch across the parenchyma, and doubtless these serve as 
protractors and retractors of the pharynx. (c) A third set of fibers 
are conspicuous in horizontal sections, running longitudinally as to 
the body among the vitellaria, often branching. I have not succeeded 
in recognizing the attachments of this system of fibers. The visceral 
portions of the musculature will be taken up in connection with the 
related organs. 
C. insignis. is not favorable for the study of muscle histology, 
but some points were noticed that may be recorded. Fig. 13 is a 
view made from a methylene blue preparation showing a long and 
slender muscle fibre in connection with a nucleated muscle cell (as 
in the myoblast of Srarrorp fig. 26). This cell was one from among 
the longitudinal musles of the body-wall. Transverse sections of 
muscle fibres furnished indications of fibrillation and a ground sub- 
stance in which the fibrillae are imbedded. Perhaps also views like 
Fig. 12, which are obtained in various places from sections deeply 
stained with iron-haematoxylin and then strongly decolorized, may 
be accepted as evidence of fibrillation. The alternation of stained 
and unstained areas in such cases is a marked feature in the 
14* 
