No. 32.— 1886.] SCIENTIFIC RESEARCHES. 



305 



is protected in this case by the length of the spines, while 

 the above-mentioned one found protection in the poison- 

 apparatus of its host. 



During the last days of our residence in Trincomalee, a 

 sea-urchin was brought to us, which both by its size and by 

 the splendour of its colours quite surprised us. It was a foot 

 in diameter exclusive of the spines, which were two to three 

 inches long. Its height was about six inches ; on the ventral 

 surface were shorter and stronger spines than above. Its 

 colour was brownish black, and over it ran from the apex 

 downwards broad Saturn-red bands, which in the whole of 

 their length were dotted with very large splendid azure spots ; 

 these spots we discovered to be eyes, as in the case of 

 Diadema. This gigantic sea-urchin has up to the present 

 no rival, as far as we can learn from the literature on the 

 subject. Probably it was brought up from a great depth to 

 the shore by the strong current of the north-east monsoon. 

 Should it prove, after a more exact systematical examination, 

 to be a new species of the genus Diadema, we would propose 

 to give it the name of Diadema imperator. 



