308 COMMON OBJECTS OF THE SHORE. 



Scarcely larger than this is the Purple-tipped 

 Urchin (Echinus miliaris), which is often found 

 with the common egg-urchin on oyster-beds or 

 scallop-banks, and is sometimes mistaken for the 

 young of that animal, but may be known from it 

 by its much larger purple spines. It is rose- 

 coloured, with white tubercles; some of the 

 spines purple, and others yellow. This, though 

 very abundant in the Irish Sea, and on the south- 

 western shores of Scotland, is not a frequent 

 English species. 



There are a number of less known kinds of sea- 

 urchins, distinguished by names significant of their 

 form, or of some peculiarity in their appearance. 

 Thus we have Heart urchins, and Fiddle-heart 

 urchins, and Cake urchins ; names all expressive 

 of the shape. And we have the Silky-spined 

 urchin, well named from the bright glossy lustre 

 of its spines ; and the Rosy-heart urchin, whose 

 colour might vie with that of the queen of flowers. 

 Of the four British species of Heart-urchin, one is 

 very common and diffused through all the Euro- 

 pean seas. Most persons accustomed to roam about 

 in those sandy bays so delightful to the marine 

 zoologist, have seen sea-eggs of this species thrown 

 upon the shore, after the angry waves have spent 

 their wrath upon it. The common Heart-urchin 

 or MermaidVhead (Ampkidotus cordatus), is also 

 otten called Child^s-head urchin, or hairy sea-egg. 

 It is broadly heart-shaped, much depressed in the 

 middle, and thickly set with fine hair-like spines. 

 Its colour is a yellowish white, and it is usually 

 about an inch and three quarters long, and very 

 nearly of the same breadth. These animals, and 

 some others of a similar nature, were found, on 



