ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 577 



INVERTEBRATA. 



MoUusca. 

 0- Cephalopoda. 



New Type of Cuttlefish.*— Carl Chun describes Cirrotkaima 

 nnirrayi g. et sp. n., a remarkable type discovered by the ' Michael 

 Sars' Expedition (1910). It is a perfectly gelatinous semi-transparent 

 Cephalopod, the fragility of which recalls that of a Ctenophore. 

 The gelatinous body exhibits an exceedingly faint violet colour, and 

 only the parts round the mouth, the proximal section of the arms, and 

 the web, exhibit the purple chocolate colour peculiar to many deep-sea 

 forms. Chromatophores are lacking, with the exception of a large 

 rhombic one situated on the ventral side between the two fins. 



A unique feature is the presence on the inner side of the arms of 

 thirty-six minute suckers, poised on long spindle-shaped and clumsy 

 stalks of gelatinous substance. They are evidently out of function, being 

 flattened and devoid of the sucking pit, and smaller than the normal 

 proximal suckers. In the middle part of the arm each spindle-shaped 

 sucker-stalk shows (1) gelatinous connective-tissue with (2) isolated 

 strands of longitudinal muscles branching distally in a dichotomous 

 manner ; (3) outside these a system of exceedingly fine ring muscles ; 

 (4) in the interior capillary vessels ; and (5) a whitish structure situated 

 in the proximal third part of each stalk. 



The whitish structure consists of a gristly shell, the aperture of 

 which is filled with a ball-shaped cellular body. It may be that the 

 shell represents a reflector, and the ball-shaped agglomeration of cells 

 a luminous body. 



The eye is only 3 mm. in diameter ; it is devoid of a lens and 

 ciliary body ; the ganglion pedunculi and ganghon opticum are lacking ; 

 the optic nerve exhibits extreme degeneration. Furthermore, the 

 retina or layer of rods also exhibits excessive degeneration. Thus the 

 rods, which in other Cephalopods are densely crowded and firmly welded 

 together, are widely separated from each other. They are strangely 

 short and generally a little pointed at the free end, projecting like 

 minute flames from the pigment-layer. A large black body behind the 

 rudimentary eye is a venous sac. It may be said that Cirrothauma is 

 the only blind Cephalopod known, and that the degeneration of the eye 

 has gone far — farther than in many blind Vertebrates. The type seems 

 suited for abyssal life, and 3000 metres of wire were out when it was 

 captured. 



Larvae of Spirula.t — Carl Chun describes the external features of 

 the Spirilla larvae captured by the 'Michael Sars' (1910) expedition in 

 the vicinity of the Canary Islands. The youngest was 6 mm. long, with 

 five visible chambers. In regard to these very young forms attention is 



* Rep. 'Michael Sars ' Exped., iii. pt. 1 (Zoology) 1913, pp. 1-28 (2 pis. and 

 11 figs.). 



t Rep. 'Michael Sars ' Exped., iii. pt. 1 (Zoology) 1913, pp. 14-17 (2 pis. and 

 2 figs.). 



Dec. 17th, 1913 2 Q 



