196 HABITS OF SOME ATJSTRALIAl^ ECHINI, 



None of the wounds bled as tlie puncture is so very fine. It is 

 useless to try to extract tlie fragments as they break into pieces 

 as soon as they enter the flesh. I suffered no inconvenience from 

 them after a day or so, and don't know what became of them. 



Centrostephanm Rodgersii, A. Agassiz, is one of the few species 

 which appears to have a very restricted habitat. It is common 

 at Port Jackson and Botany Heads, and on the coast between, 

 but I do not know of any other place where it is found on the 

 east coast. Doubtless this is only because we know so very little 

 of the coast fauna. When a closer examination is made other 

 habitats will surely be found. It is a very handsome urchin of 

 the deepest purple, or almost black colour. The spines seem all 

 of one kind, and being rather stout are closely packed, besides 

 being long and gracefully tapering. They are grooved with 

 transverse rings or serrations, hollow and so thin that a very 

 slight touch breaks them. The test also is very thin and easily 

 destroyed. The animal generally lives in rocky crevices or over- 

 hanging ledges. It clings to the rock with its powerful suckers 

 with the surface free. It is very careful to select as a place of 

 repose a very narrow cell with just room enough for its body. 

 The projecting spines can be seen, but it is only on the rarest 

 occasions that it can be drawn from its recess uninjured. It 

 adheres with great tenacity, and any attempt to detach it crushes 

 the spines and the test. It emerges from these fastnesses to feed 

 on the sandy bottom when the tide is in. It can then be easily 

 captured and is often overtaken by storms and thrown up on the 

 beach in a nearly perfect condition. 



Astrojyyga radiata, Leske, has a very soft- thin test and a few 

 short thin spines. It seems to feed on the mud, but I know 

 nothing more of its habits. Its only Australian habitat is in 

 Torres Straits, and then few specimens were found together. 



Jleterocentrotus mammillatiis, Klein., does not seem to be rare on 

 the Australian coast wherever coral reefs are found. Its habits 

 are much the same as Echinothrix calamaris. It lives among the 



