SOME SEA URCHINS. 



The Sea L'rchins have their principal organs enclosed in a wonderful stronti box, built up of five-sided pieces joined edge to ed^^e, and 

 bearing on ihe outside multitudes of spines, which are movable at the will of the animal. The Urchins move about by means of thousands 

 of tiny suckers protruded through minnte perforations of the shell- The upper left-hand fitiure is a native of Mauritius ; the lower, which is 

 t-rne/j on its back, is from Fiji, On the right hand the top species is found in the Straits of Magellan; below it, a purple-spined European: 



and the lowest, with thorny spines, is from Port Jackson. 



