ECHINODERMATA 77 



out : water in which one has been cleaned for preservation 

 looks as if mixed with a purple dye. 



This species lives on, or just below, the surface of loose 

 shell gravel, from near low- tide margin to deep water. 



On some shores e.g. the shell reaches of Herm Island, 



Fig. 32. Denuded test of Spatangus purpureus 

 ^ Natural size 



some parts of Grouville Bay, Jersey, etc. it is very 

 common on that part of the shore laid bare at the period 

 of the equinoctial tides. 



Amphidotus cordatus is a smaller species, more abundant 

 than the last, or at least more generally diffused. It is 

 about three inches long by two inches wide, and is rather 



