EVOLUTION 123 



/Eolididae have stinging cells, like those of the Jelly- 

 fish and Anemones, at the tips of their cerata. These 

 creatures are conspicuously marked with what may 

 be warning colours, and do not seek concealment. 



Of mimicry proper, in which an animal seeks to 

 resemble some surrounding object or some other and 

 distasteful congener, some instances are met with 

 among the Mollusca, and others will doubtless be 

 forthcoming with more careful observation. 



It has been suggested that some of the Land 

 Snails, like Clausilia and certain of the Pupillidae 

 ( = Pupid9e), as well as some Slugs, may derive a 

 certain amount of protection from their passing 

 resemblance to the fallen leaf-bud scales of trees, 

 while some Helices closely simulate the seed-pods 

 of the plants which they frequent. One of our 

 Common Shore Periwinkles (Littorina obtusata) is 

 thought to resemble the air bladders on the seaweed 

 (Fucus), among which it dwells. Lamellaria perspicua, 

 a taenioglossate mollusc with internal shell lives on 

 Ascidians, and in coloration and markings accurately 

 reproduces the appearance of the colonies of its 

 victims. Conspicuously coloured Nudibranchs like 

 Doto coronata and Dendronotus frondosus closely 

 resemble colonies of Hydroids among which they 

 dwell. Jorunna Johnstoni lives associated with a 

 sponge (Halichondria panicea), for the little colonies 

 of which, it is readily mistaken. Now, Hydroids 

 have stinging cells, and the Ascidian in question, as 



