Sea-slugs 289 



The .slieaths of the rhinophores, and tlie front of the 

 head, are cut into simihir forms. It is about \h 

 inch long. It is said to be highly edible, having 

 nothing in its flavour to displease the taste of the 

 most fussy fish ; and therefore its disguise is 

 absolutely necessary to the species. The colour 

 varies, but most frequently it is red marbled with 

 brown and with white or yellow spots. The liver 

 does not extend to the cerata. It occurs between 

 tide-marks and in the laminarian zone among sea- 

 weeds and corallines. 



The Crowned Sea-nymph {Boto coronata) feeds 

 upon Hydroids and Corallines, and consequently 

 harmonises closely with them in general form and 

 colour. The body is slender, but from each side 

 there extends a number of narrow lobes which bear 

 the bright coloured cerata. The liver is entirely 

 contained in these cerata, which render the animal 

 very conspicuous Avhcn taken from its habitat, but 

 this is the under-sides of large stones and rock-ledges 

 where grows Clava multicoriiis in abundance, and 

 its tentacles and sporosacs are closely mimicked by 

 the cerata and markings of Doto. In deeper water 

 it will be found to preferably afl'ect the Sea-firs 

 (Sertularia and Pliimidaria), The tentacles are 

 slender, and issue from long vase-like sheaths. There 

 are no true branchic>3. It is only half an inch in 

 length. D. fragilis is 1 inch long, more robust 

 in form, and coloured a dirty yellow, spotted Avith 

 white. There are nine pairs of cerata, and these 

 individually bear a very close resemblance to the 

 Hydra tuba stage of certain Jelly-fishes. It feeds 

 upon corallines, especially that named Lobster-horn 



