180 THE SEA SHORE 



collector with the aid of friendly fishermen, who sometimes find 

 it plentifully among the contents of their trawl nets. Failing 

 such aid, it may be looked for among the encrusted stones that 

 are exposed only at the lowest spring tides, especially in places 

 where a certain amount of mud has been deposited under the 

 shelter of outlying rocks ; and the chances of success are much 

 greater if the search is made immediately after a storm, for at 

 such times much of the life that exists in deep water will have 

 been driven shoreward by the force of the waves. 



At first sight the sea mouse would hardly be associated with the 

 worms ; for, instead of having the elongated and cylindrical form that 

 is usually regarded as characteristic of these creatures, it is broad 

 and slug-like in shape, the under surface, on which it crawls, being 

 flat, while the upper side is convex. The segmentation of the body, 

 too, is not readily seen in the upper surface on account of the thick 

 felt-like covering of hairs, but is at once apparent when the 

 creature has been turned over to expose the ventral side. 



When seen for the first time in its natural haunt one naturally 

 wonders what the moving mass may be. Crawling sluggishly over 

 incrusted stones, or remaining perfectly still in a muddy puddle 

 that has been exposed by overturning a stone, it looks like a little 

 mound of mud itself, about four or five inches long, and its general 

 colour and surface so closely resembles that of its surroundings 

 that an inexperienced collector may never even suspect that the 

 mass is a living animal form. But take the creature and wash it 

 in the nearest rock pool, and it will be recognised as a broad 

 segmental worm, thickly covered with fine hairs above, and its 

 sides adorned by bristles that display a most beautiful iridescence. 

 It is not easy to see the value of this gorgeous colouring to the 

 animal, and it is doubtful whether, on account of the muddy nature 

 of the creature's home, such colouring is often displayed to the 

 view of other inhabitants of the sea ; but it is well known, on the 

 other hand, that sea mice are readily devoured by fishes, even 

 though they possess an armature of stiff and sharp spines, and that 

 they must therefore be often preserved from destruction by the 

 close resemblance of the general colour to that of their surroundings. 



The gills of the sea mouse are not prominent appendages, as 

 with most marine worms, but are soft fleshy structures situated 

 beneath the overlapping scales that lie hidden below the thick hair 

 of the upper surface. 



As it is most probable that the reader may desire to preserve 



