24 DR. R. E. GRANT ON THE GENUS LOLIGOPSIS, 
The parietes of the mantle are remarkably thin and loose, excepting where they are 
supported by the dorsal transparent lamina, and by two thin cartilaginous lamine, ex- 
tending half way down the sides of the mantle. The dorsal lamina! is thin, transparent, 
convex externally, carinated along its middle, narrowest about the middle of the trunk, 
expanded laterally on the caudal half of the trunk in which the viscera are lodged, and 
tapers gradually to a narrow point as it passes along the middle of the circular caudal 
fin, to the lower extremity of which it extends. The two lateral thin /amine present here 
an appearance anomalous in Cephalopods ; they extend longitudinally from the free edge 
of the mantle, where the valvular expanded base of the syphon is attached internally, 
to about half way to the tail. They are placed rather towards the ventral surface of 
the mantle, so that the warty projections which they send out are seen in the front view 
of the animal. To the eye these lateral Jamine are almost imperceptible ; but they are 
obvious to the feel, from the stiffness they produce along their course. Each of these 
lamine sends out twelve or thirteen conical tubercles? about a line in diameter at their 
base, which extend to the distance of a line beyond the general surface of the mantle. 
Between each of these twelve large transparent cartilaginous warty tubercles, there are 
three minute projecting parts of the same substance, the middle one of these three being 
larger than the others, so that the whole of this line of the mantle presents a continuous 
row of hard rough conical prominences, the use of which in an animal otherwise suf- 
ficiently provided with organs of progressive motion, it is not easy to conceive. When 
we look through the mantle from the inside along the line of these tubercles, it appears, 
from the transparency of the cartilaginous substance composing them, as if there were 
twelve circular openings on each side; the tubercles, however, are quite solid, and have 
a very rough warty external termination. From their connexion with the lateral lamine 
and their regular position, they can scarcely be considered as analogous to the dorsal 
general cutaneous roughness of some other Octopods. The head of the animal is sup- 
ported behind by its close attachment to the upper expanded termination of the dorsal 
lamina. The sac containing the viscera tapers from the middle, where it is widest, to 
the beginning of the tail, and continues very narrow along the inferior surface to the 
extreme point of this nearly circular caudal appendix. The length of the tail is about 
a sixth of the whole length of the animal; it consists of two semicircular fins, ex- 
tending laterally from the posterior termination of the body. These fins are attached 
to the dorsal surface ; they are supported by the tapering portion of the dorsal lamina 
throughout their whole extent ; and by following that /amina to its extremity, they are 
drawn a little out so as to terminate the body in an obtuse point. 
The viscera occupy but a small part of the cavity of the mantle, and are placed far 
back in that cavity, the branchie themselves not extending forwards beyond the middle 
of the sac. The parietes of the lower part of the @sophagus are thin, loose, transparent, 
and with internal longitudinal slight plice of the mucous coat. The esophagus? narrows 
1 Fig. 2. 2 Fig. 3. SO tec 
