THE 



JOURNAL OF MALACOLOGY 



No. 2. JUNE 29th, 1895. VoL IV. 



THE HABITS OF THE YOUNG SEPIA. 



By FRANXIS A. BATHER, ^LA., F.G.S. 

 Bvitish Museum (Natural History), Loudon. 



I send you a page and some sketches from my notebook at 

 Roscoff last autumn. The notes may be of very small value, 

 but I have seen no similar observations published. 



For a day or two after its escape from the egg-capsule, 

 the young Sepia officinalis attaches itself to the floor of the 

 glass vivarium, or to other flat substances. The adhesion is 

 effected by a definite area on the ventral surface of the body 

 and of the postero-ventral arms, which area acts like a sucker, 

 or in some ways like the foot of a gastropod. (Fig. i.) The 

 area has a distinct border not identical with the fins, but about 

 one-third or half way between them and the median ventral 

 line. The area is flat and colourless, except for a few pale yellow 

 chromatophores such as are also found on the funnel and just 

 within the pallial cavity. It is bordered by the ordinary 

 chromatophores. The imder surface of the fins is quite plain, 

 but'chromatophores extend for a little distance over their dorsal 

 surface. This development of a ventral sucker is no doubt wuth 

 the object of preventing the young cuttle-fish from being swept 

 far away by currents, and is paralleled by the suckers in the 

 young of many other animals, e.g., in tadpoles. The terminal 

 disc in Spivnla, if, as some have supposed, it is really a disc of 

 attachment, may possibly have been derived from some such 

 juvenile sucking habit. Pelseneer, however, denies this function 

 to the terminal disc. 



