Echinoderms from Port Phillip. 405 



Plectaster decanus. 



T was able last year to note the presence of Echinaster de- 

 canus in the waters of Port Jackson (Proc. Linn. Soc. N. S. 

 W. [2] ii. p. 1074) ; the affinities of the species will be dis- 

 cussed by Mr. Sladen in his forthcoming ' Challenger ' Re- 

 port ; he informs me that he has instituted a new genus, 

 which he calls Plectaster^ for its reception • this is quite in 

 accordance with the expectation of Dr. E. P. Ramsay, who is 

 reported {loc. cit.) to have expressed his opinion as follows : — 

 " although closely allied to Echinaster^ I believe it will even- 

 tually find its way into a new genus." 



Palmipes, sp. 



Here we have a small specimen too young to be definitely 

 determined. I cannot think it to be tlie young of Pa/m«}>es 

 in/latus, Hutton, though, like it, it has the adambulacral 

 spines imbedded in the integument. It is probably an imma- 

 ture example of an undescribed species. 



Microcyphus zigzag. 



A small specimen of this species, with a diameter of less 

 than 10 millim., has the test of a most beautiful rosy colour, 

 which does not appear to be lost by preservation in alcohol. 



StrongylocentrotuSj sp. 



There is a single small specimen which, with a little hesi- 

 tation, I refer to this genus ; it is remarkable for the thick 

 covering of scales found on the buccal membrane. Mr. A. 

 Agassiz defines the genus as having the membrane bare. 

 As, however, the specimen is young, and bearing in mind 

 the variations presented by different specimens of Echinus^ I 

 think we may regard this as an immature example of what 

 will probably be found to be a new species of Strongylocen- 

 trotus. The spines are white, rather short, and rather stout. 



Afolpadia, sp. 



There is, unfortunately, only one example of a species of 

 this genus ; it is not, I think, the same as Mol^yadia australiSf 

 Semper, for its spicules are much more regular ; a more cora- 



Ann. & Mag. N. Hist. Ser. 6. Vol. ii. 28 



