MARINE BIOLOGICAL STATION AT PORT ERIN. 101 



The two remaining animals shown in fig. XIX. are 

 Cuttlefishes (Cephalopoda). No. 5 is the common squid 

 (Loligo vulgaris), with 8 short " arms " and 2 longer 

 " tentacles " attached to the head, and all of them bearing 

 suckers. Loligo has an internal shell shaped like a 

 short Roman sword, and made of a flexible transparent 

 horn-like substance. The remaining Cephalopod (No. 6) 

 is a kind of " Octopus " called Eledone cirrhosa. It has 

 only the 8 sucker-bearing arms, the body is shorter and 

 rounder than in the squid, and there is no shell of any 

 kind external or internal. 



The soft skin of the Cuttlefishes is coloured yellow, 

 red and brown by little sacks full of pigment grains, and 

 these sacks can be so varied in shape as to change the tint 

 of the animal in accordance with its surroundings. In 

 little baby cuttlefishes from \ to \ an inch, in length this 

 instantaneous change in colour, or " blushing," can be 

 seen most beautifully as the little animals just hatched 

 from the egg dart about the tank from darker to lighter 

 coloured parts. 



Some Gastropods, such as the sea-hare (Aplysia 

 punctata), found by dredging in the bay, have very small 

 shells which do not cover the body. 



The common limpet (Patella vulgata) is frequent on 

 the shore, and the beautiful transparent brown Helcion, 

 with its radiating lines of delicate turquoise blue, is found 

 at low tide on the blades and stems of the oar-weed. 



Reports upon the various groups of Mollusca, by Mr. 

 11. 1). Darbishire, Mr. F. Archer, Mr. W. E. Hoyle and 

 Mr. A. Leicester will be found in the volumes of our 

 " Fauna." 



There is one set of Molluscs related to the ordinary 

 univalve Gastropods which have lost their shells. These 

 are the Nudibranchs or sea-slugs, four common kinds of 



