726 



THE HEART-URCHIN. 



In some of the hotter parts of the world, such as the Indian seas, several species of 

 Echinus are armed with sharp and slender spines, which are apt to pierce the bare 

 foot of a bather, and to cause painful, and even dangerous, wounds. Most of these 

 Echini live in the crevices of rocks, but sometimes crawl over the sand, and inflict much 

 suffering upon those who unwittingly place a foot upon them. Mr. F. D. Bennet, in 

 his account of a " Whaling Voyage," had practical experience of these sharp spines : 

 " On one occasion, when searching for fish in the crevice of a coral rock, I felt a 

 servere pain in my hand, and, upon withdrawing it, found my fingers covered with 

 slender spines, evidently those of an Echinus, and of a gray color elegantly banded 

 with black. They projected from my fingers like well-planted arrows from a target, 



COMMON HEART-URCHIN. (Without Spines.) PURPLE HE ART-URCHIN. -Spataagus purpureus. 



FIDDLE HEART-URCHIN. Brlssus lyrifer. COMMON HEART-URCHIN.- Amphldotus cordatus. 



FIDDLE HEART-URCHIN. (Without Spines.) 



and their points, being barbed, could not be removed, but remained for some weeks 

 imbedded as black specks in the skin. 



Its concealed situation did not permit me to examine this particular Echinus, but I 

 subsequently noticed others of a similar nature fixed to the hollows in the rocks ; they 

 were equal in size to the Echinus ridaris, and their body was similarly depressed, but 

 the spines were long, slender, and more vertically arranged, and their points finally 

 serrated. Their color was jet black. These animals adhered so firmly to the rocks, 

 that they could not be detached without difficulty. 



When closely approached, they gave an irritable shrug to their spines, similar to that 

 displayed by he porcupine or hedgehog. It was difficult to say if the hand had been 

 brought in perfect contact with this Echinus before it was wounded by its weapons. In 

 some experiments, I approached the spines with so much caution, that had they been the 



