69 
the outgrowths on the mantle, looking exactly like the polyps of 
the coral, combined result in concealing the animal in the most 
perfect way. I have made exactly the same observations on another 
species in the Gulf of Panama, viz. Ovulum (Volva) aciculare 
Lam. There is no reason to describe this case in detail, as it 
would simply be a repetition of the description given by Osborn; 
it may only be stated that I had at that time no knowledge of 
Osborn's observations, in order to show how any observer must 
be struck by this case of protective resemblance. 
Also another fine instance of protective resemblance in Mol- 
luscs was observed here, namely the beautiful little Cypræa pust- 
ulata Lam. found on the corals in Panama Bay (Fig. 4). The skin 
folds are set with small, branching protuberances, Cco- 
loured exactly like the polyps of the coral; when 
Creeping undisturbed the snail thus resembles the 
Coral in a very perfect way. Also the remarkable 
Coloration of the shell itself, the yellowish brown 
tubercles on a greyish white bottom may perhaps be 
regarded as a protective coloration; at least it is 
not very. easily seen on the corals. 
It is especially noteworthy that among the nume- 
TOus gorgeously coloured Nudibranchs observed not 
one undoubted case was noticed, where the colour served as a 
means of protection. On the contrary, many of them are very 
Conspicuous, so that one would sooner be inclined to think the 
Coloration to be of the warning character. It may be possible, of 
Course, that some species are unpalatable, as it has been proved for 
Some forms from the British seas (Beddard, Op. cit. p. 174) but 
Still I would prefer to regard the gaudy coloration of so many large 
Nudibranchs as not to be explained by any of our present theo- 
ries, as M'Intosh!) justly says: ,That the coloration often so 
varied and so beautiful, is of importance to marine animals can 
Scarcely be doubted, for Nature is ever prescient?); but it is not 
always easy to adapt the theories of the day to her workings.” —- 
Å very god. instance of protective coloration was afforded by an 
Elysiid found on the sandy flats inside the reef at Honolulu. The 
Fig. 4. Cypræa 
pustulata Lam. 
Nat. size. 
) W.C. MIntosh. The coloration of marine animals. Ann. Mag. Nat. Hist. 
7. Ser, VII. 1901. p. 240. 
”) I don't know about that; Prof. MIntosh must know. 
