236 The Naturalist of Cumbrae. 



A further observation on this same urchin, com- 

 municated to the Glasgow Natural History Society 

 in 1880, may be here quoted : 



"The common heart-urchin, Amphidotus cordattts 

 (Pennant), found so commonly lying dead along our 

 sandy shores, denuded of its spines, has a feature in 

 its habits that I do not know has been noticed before. 

 They burrow from about four to six inches into the 

 sand, and when dug up and put into a vessel with 

 sand covered with sea-water, the animal is seen at 

 once to commence to throw the sand to the sides by 

 the under or plastron spines. By the time that it 

 gets down into the sand, level with the under edges 

 of the test, the spines of the body get into motion, 

 forming into four or five, sometimes six or seven, 

 ridges of spines, which stretch from back to front 

 along the sides of the test, progressing upwards in 

 wave-like fashion, and following each other in regular 

 succession till .they reach the superior avenue or 

 summit. Each wave, as it emerges from the sides of 

 the animal, brings up a roll of sand to the surface, 

 which falls outward, and this action is continued till 

 the animal is completely covered. When newly dug 

 out of the sand, they often work rapidly down into it, 

 apparently by the ventral spines, without calling into 

 aid the formation of the lateral ridges of spines." 



To repeat and enjoy these observations it is not 

 necessary to be a philosopher or a man of science. 

 It will suffice to have a disposition to some degree 

 sympathetic with the lower forms of life, and to have 

 the living specimens. The sympathy will grow and 

 kindle with the very process of observing. For 



