298 Shell Life 



than the others. The dorsal tentacles bear about two 

 dozen oblique plates, one half of which are imperfect. 

 Both body and cerata are liberally sprinkled with 

 opaque white dots. An allied species, Cahna glau- 

 coides, is said by Hecht (quoted by Cooke ^) to imitate 

 " the ova of certain fishes on which it feeds. Its 

 elongated and depressed form of body, transparent 

 integuments, and silvery grey papillae [cerata] combine 

 to give it a strong resemblance to the spawn of 

 the fish, which is deposited on stones, tlie roots of 

 Laminar la, etc." 



The Noble iEolis (Fiona marina) is long and 

 slender, the tentacles all slender, and the sides of 

 the back irregularly clothed with compressed narrow 

 cerata of transparent buft' with a centre of rich brown 

 and tips of opaque bluish white. The whole creature 

 has a lustrous appearance. 



The Crested ^olis {Antiopa cristata) is a deep- 

 water species of a transparent pale yellow tint in- 

 clining to buif. The dorsal tentacles are covered 

 with oblique plates which meet behind. The "crest" 

 is found uniting these tentacles, and is arched and 

 lobed. The transparent cerata show a narrow core 

 of brown, and pointed tips of white which gradually 

 changes into ultramarine a little lower. It is IJ 

 inches long. The other native species (A. liyalina) 

 is only one - fifth of that size, very transparent, 

 yellowish with red-brown spots and mottlings. The 

 cerata are rugged, and lack the white and blue tips. 



The genera Proctonotus and Hero — each repre- 

 sented by a single species — complete the family 

 ^olidiidae so far as it is represented on our shores. 

 ^ Cambridge Natural History, vol. iii. p. 74. 



