hoyle: reports on the cephalopoda, 37 



side of the cartilage in the nuchal region are perceptible, though faint, a 

 character which in this species differs from A. pfefferi Jouuin. 



A colored figure of this individual from a sketch made on board whilst the 

 animal was alive will be found on Plate 1, Fig. 3. 



The characters of the arms have not beeji very minutely described either by 

 Joubin or Pfeffer. The order 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 breailth just beyond the miiklle 

 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, wliich 

 extends almost to their extremities. Along the edge of the proximal niniety 

 of each lappet, just where the web joins it, is a row of minute conical jtapillae 

 (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 (juite close to the tip. 



The fourth arm (Plate 8, Figs. 4, 5) presents considerable differences from the 

 others. It is distinctly longer and the hooks are smaller, and there are no 

 suckers at the extremity. On the dorsal margin of the hook-bearing face is a 

 low irregular elevation, which looks like a vestigial protective membrane : it 

 extends from a point opposite the proximal book to about two-thinls up the 

 arm. On the ventral maigin a narrow membrane extends along the middle 

 third. On the dorso-external asjiect 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 etjual 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 ('96). 



Two other specimens 1 take to bo males of the same species. The general 

 arrangement of the arms is the same. The spi'cimens 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 a larger or smaller number of small papillae, which look at 

 first sight almost like the sUilks from which suckers have fallen. There is, 

 however, no indication of any solution of continuity in the surface, and in no 



