HOYLE: REPORTS ON THE CEPHALOPODA. oT 
side of the cartilage in the nuchal region are perceptible, though faint, a 
character which in this species differs from A. pfefferi Joubin. 
A colored figure of this individual from a sketch made on board whilst the 
animal was alive will be found on Plate 1, F'ig. 3. 
The characters of the arms have not been very minutely described either by 
Joubinor Pfeffer. Theorder of the arms in the present specimen is 4, 2, 3, 1, 
on the left side, whereas on the right side 4 is much shorter, and the order is 
2, 3, 1, 4. The first (Plate 8, Fig. 3) arm has a keel for about the distal two- 
thirds of its length, which attains its greatest breadth just beyond the middle 
of the arm, being there rather broader than the thickness of the arm. Along 
the ventral margin of the sucker-bearing face is a series of lappets, one oppo- 
site to each hook, whose maximum length is about equal to the diameter of 
the arm in its middle: these become gradually shorter toward both the distal 
and proximal ends of the arm. They are united by a delicate web, which 
extends almost to their extremities. Along the edge of the proximal moiety 
of each lappet, just where the web joins it, is a row of minute conical papillae 
(Fig. 7). The hooks are about fifteen in number, and at the end of the arm 
is a patch of minute suckers arranged in two rows (Fig. 8). The second arm is 
in all essential respects similar to the first. 
The third arm (Plate 8, Fig. 2) is much stouter than any of the others, and 
has a very broad keel, expanding into a swimming membrane throughout the 
whole of its length. The lappets on the ventral margin of the sucker-bearing 
face are longer, stouter, and. blunter than in the first arm and are united by a 
web in the same way. On the ventral surface of the arm close to the attach- 
ment of the keel are several patches of two to five luminous organs, a group of 
three being found quite close to the tip. 
The fourth arm (Plate 8, Figs. 4, 5) presents considerable differences from the 
others. It is distinetly longer and the hooks are smaller, and there are no 
suckers at the extremity. On the dorsal margin of the hook-bearing face is à 
low irregular elevation, which looks like a vestigial protective membrane ; it 
extends from a point opposite the proximal hook to about two-thirds up the 
arm. On the ventral margin à narrow membrane extends along the middle 
third. On the dorso-external aspect of the arm is a membrane which springs 
from the root of the third arm, passes outside the tentacle, and is attached 
along the fourth arm almost to its extremity, becoming gradually narrower as 
it proceeds. The breadth at the base is about equal to the diameter of the 
arm. At the extremity are the three black, bead-like knobs, characteristic of 
the genus, the structure of which has been described by Joubin (796). 
Two other specimens 1 take to be males of the same species. "The general 
arrangement of the arms is the same. The specimens are not so well pre- 
served, and the delicate web between the lappets along the margins of the arms 
has been in a great part destroyed. At the base of each arm just proximally 
to the suckers is à larger or smaller number of small papillae, which look at 
first sight almost like the stalks from which suckers have fallen. There is, 
however, no indication of any solution of continuity in the surface, and in no 
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