452 Mr. E. S. Russell on tJie Cephalopoda 



of the mantle miJ-tlorsally to the insertion of the fins is 

 1G"5 mm. ; its greatest breadth is about halfway along the 

 back, where it measures 11*5 mm. In front the dorsal edge 

 of the mantle is transverse, with a sinuous margin, and 

 measures G*5 mm. across. It is distinctly produced at the 

 corners and curved sliarply back in tlie middle line, where it 

 is fused with the head. The ventral margin of the mantle 

 exhibits two deep bays laterally where it is fused with the 

 siphon, and in the middle it is produced forward in a small 

 flap-like process. The mantle is very delicate and trans- 

 lucent, of a clear whitish tinge in formalin, probably quite 

 transparent during life. On the back there are a few oval 

 chromatophores of large size (up to 2 mm.) : one is situated 

 at the fusion of mantle and neck, and along the lateral 

 margins there are about five on each side. On the ventral 

 surface the chromatophores have a similar arrangement — a 

 pair opposite the base of the funnel, a pair behind and 

 external to these, then two or three on each lateral margin, 

 and three or four near the base of the tail. 



The organs of the body seem confined to the anterior two- 

 thirds of the mantle-sac. The musculature is reduced. In 

 the posterior third thtre are delicate transverse bands or 

 hoops of muscle; the anterior tw-o-thirds are more muscular. 



The neck and head are continuous and very narrow ; the 

 distance from the mantle to tlie circle of arms is 3 mm,, and 

 the head is only slightly swollen at the insertion of the large 

 stalked eyes. It is only 1"4 mm. broad below the arms. In 

 the median line dorsally are two chromatophores, and another 

 lies close below the origin of the first pair of arms. Ventrally 

 the funnel covers over another small cliromatophore. 



The eye-stalks are very large, 3 mm. in length, 1*8 mm. 

 broad in the middle, while external to their insertion on the 

 head they exhibit a swelling. There is a large and con- 

 spicuous squarish chromatophore on the dorsal surface of 

 each stalk, red round the edges, but appearing dark in the 

 centre owing to the pigment of the eye shining through. 

 The eyes show iridescent pigments — red, yellow, green, 

 purple, and dark blue. 



The funnel is large and reaches forward to about half the 

 length of the eye-stalks. It measures 4*5 mm. across at its 

 base. 



The arms form a circle round the mouth, which in this 

 specimen protrudes a little and is surrounded by a thick 

 frilled sheath. The arms are very small, and are unwebbed 

 and without fins. The two lateral pairs are tlie largest. 

 The lengths of the arms are 2 mm., 2-b mm., 2'7 mm., and 



