212 NATURAL HISTORY OF OUR SHORES 



tective. So powerful is this odour that repeated washings 

 fail to remove it from the hands after touching a 

 specimen. 



Its eggs are within capsules, in long strings, constricted 

 at intervals of about a quarter of an inch. These strings, 

 which are of a pink tint, may frequently be seen, like 

 tangled skeins of twine, among sea- weeds and stones, at 

 all parts of the shore, 



A larger species (Aplysia depilans), six to eight inches 

 long, and of a greyish brown colour, is also met with, but 

 some authorities do not consider that it is a distinct species, 

 but simply a variety. It feeds chiefly on the sea-grass 

 (Zostera), biting off and swallowing pieces about half-an-inch 

 in length. 



Pleurobmnchus membranaceus and Pleurobranchus 

 plumida are somewhat allied forms. The former, of brown 

 colour, about three inches in length, is rarely taken on 

 shore, but is frequent in the dredge. The latter, about 

 half this size, of a beautiful, waxy, almost transparent, 

 yellow, is found in the littoral, under stones in rock pools. 

 These have a beautifully striated internal shell. 



Philine aperta, Lamelligera perspicua, and one or two 

 other small forms allied to these, occur under stones and 

 among corallines at low-tide limit. 



The Nudibranchiata. These are .represented on our 

 shores by about twenty species, the most familiar of which 

 is Doris tuberculata (the " Sea-lemoD " Fig. 91). This is in 

 shape, size, and colour very much like half-a-lemon, except 

 that the gills, in the form of a beautiful tuft of plumes, arise 

 from near its posterior end, and a pair of earlike tentacles 

 from the anterior. It is tolerably common on most rocky 

 coasts, crawling over rocks and boulders in sheltered 

 situations. It feeds on sponges, and is the only animal, 

 as far as I am aware, that does so. 



It is curious, in dissecting a Doris, to see how the stomach 



