CEPHALOPODA FROM THE CALCUTTA MUSEUM. 17 



Taonius abtssicola, n. sp. (PI. 5. figs. 72, 73, 71^, 75, 76, 77, 78, 79, & 80.) 

 Two sj)ecimens from the Laccadive Sea belong to this genus. The first, the large 

 specimen shown in figure 72, comes from a depth of 902 fathoms. It is somewhat 

 injiu*ed ; the skin has been rubbed off the mantle, fins, and head, and the eyes have burst 

 out of their lids. The second specimen, from a depth of 1370 fathoms, is very much 

 smaller and in a less satisfactory state of preservation. 



The principal measurements of the large specimen are as follows : — 



Length of mantle (lowei- surface) 7*6 centim. 



Breadth „ near edge 3-8 „ 



Length of fin-attachment 2*4 „ 



Breadth across combined fins l-~ ^^ 



„ of head between eyes '7 „ 



„ across eyes 2'8 „ 



Length of dorsal arm 2'5 ,, 



„ dorso-lateral arm 2'8 ,, 



„ ventro-lateral „ 3"3 „ 



„ ventral „ 2-8 „ 



„ tentacular „ 4'2 ,, 



„ >, club 1-1 ,, 



The mantle is loose, enclosing an ample cavity ; it diminishes gradually to the origin 

 of the fin, and then suddenly to the narrow apex. The outline of the fins is egg-shaped. 

 The mantle is attached by a lozenge-shaped cartilaginous plate to the back of the neck, 

 and on both sides to the base of the siphon. 



The aperture of the funnel is covered by the sharply recurved upper lip (fig. 72), All 

 previous observers have described the funnel of this species as destitute of valve.* On 

 slitting up the funnel of this specimen and turning aside the two sides as shown in 

 figui-e 7i, I found that the inner and upper wall is sharply bent inwards near the opening 

 so as to form a deep pit w^here the sij)hon is fused to the head. On either side of this 

 pit are the two cushions [c) noticed by Verrill (9), which in their normal position 

 almost close u.p the lumen of the funnel. When these two cushions are pushed aside, a 

 well-developed valve is disclosed rising from the bottom of the pit (fig. 74 v.). Behind 

 the cushions, further down the funnel, are two triangular flaps, flattened and fastened 

 by their base to the sides of the funnel {t.Jl., fig. 7i) ; they appear to be of a glandular 

 nature, and probably correspond to the lateral pads described in other forms by 

 AVeiss (10). 



On the inner and upper wall of the siphon is a wide A-shaped plate — the funnel-organ 

 — very similar in shape to that figured by Weiss in Verania sicula. In the present 

 instance it was so loosely attaclied that it readily came off; it is represented in flgtire 75, 

 and its position is indicated by a dotted line in figure 74i. On the inner surface this 

 plate is produced on either side into a triangular cap {i.e.), which fits closely as a glove 



* Since this was written M. Joubin (4) has described a small valve in the siphon of a new species of Taonius 

 from the Atlantic. 



SECOND SERIES. — ZOOLOGY, VOL. VII. 3 



