THE GENERAL CHARACTERISTICS OF SHORE ANIMALS. 9 



of rocks or near the mouths of rivers, while in the long 

 stretches of clean sand most frequented by children organic 

 particles are remarkable for their absence. To illustrate the 

 variety of sand-burrowing animals, I may give a list of the 

 spoil taken by a party of which I was a member at some 

 sands in the Firth of Clyde, near Millport. We got first 

 a burrowing sea-anemone (Pe&hia), any number of heart- 

 urchins (Echinocardium cordatum) covered with beautiful 

 golden spines, Synapta, a curious pink worm-like creature 

 really allied to sea-urchins, razor-shells (Solen), otter-shells 

 (Lutraria), old maid shells (Mya), all living and active, any 

 number of ringed worms of various kinds, some ribbon- 

 worms, and many sand-eels, and all these occurred together 

 within a very limited area, and were taken in the course of 

 an hour's digging. 



FIG. 2. Sand-launce or sand-eel (Ammodytes tdbianus). After Day. 



One is tempted to say of each set of marine animals that 

 they are the most interesting of all, but surely there is a 

 special interest about sand-burro wers ! The worms, perhaps, 

 one might pass over, for the common earthworm has 

 familiarised us with the burrowing habit, but how does 

 a sea-urchin get deep down into the sand ? Those mentioned 

 above were found in one locality, living, not in sand, but 

 in a sandy gravel full of stones and shells. The shell or 

 test of the heart-urchin is as fragile as glass, so thin that 

 unless held with care one's fingers go through it. How does 

 it bore its way among sharp-edged stones without injury? 

 So with many of the others, as the spade turns them up 

 a dozen "hows" and "whys" crowd upon one. Digging 

 in the sand may seem a childish pastime enough, but if you 

 choose your sand aright it has many fascinations. 



There are many other of the more sedentary shore 

 animals which do not burrow and are not protected by 

 a thick shell. These usually settle down in damp and dark 

 situations where the sun's rays do not penetrate, or they 



