MARINE MISCELLANEA. 225 



whether the erect fascicle of elongate siliceous spicula encrusted by the polyp was 

 the product of this organism, or an integral part of the subspherical sponge body, 

 usually, but not invariably it first falling to decay found seated at its apex, was the 

 subject of a prolonged and most heated controversy in the earlier days of biological 

 investigation. The names of Dr. J. E. Gray and Dr. Bowerbank will be remembered by 

 all contemporary zoologists as the doughty champions of these respective interpretations. 



The Zoantharian discovered and described by the author also possesses the 

 somewhat unusual distinction of an erect supporting fulcrum. The fulcrum in this 

 instance is, however, altogether different in character to that of the commensal Palythoa. 

 In place of a relatively solid axis, Acrozoanthus australice is built up on a hollow 

 or tubular support of parchment-like consistence, which, when denuded of the 

 encrusting polyps, exhibits a singularly symmetrical zigzag growth plan. Its angular 

 projections are, moreover, usually developed on the same plane. The polyps in the 

 living organism invest this structure completely with their united flesh or' csenosarc, 

 but project in the most conspicuous clusters from the alternating prominences of the 

 tubular support. As figured and described in the author's original account of this 

 organism, the individual polyps are attractively coloured, the semi-contracted zooids 

 more particularly presenting a rounded button-like contour, in which the tints of bright 

 emerald green and red-brown specklings are predominant. When fully expanded, the 

 brighter green hues of the column and sphinctral regions are concealed by the radiating, 

 red-brown tentacles. 



Acrozoanthus was first collected by the writer on the foreshore at Port Darwin, 

 subsequently at Cambridge Gulf, Torres Straits, along the Great Barrier Reef, and 

 finally at Eoebuck Bay in Western Australia. It is thus shown to be indigenous to 

 all quarters of the tropical Australian sea-board, and is in that respect a fitting claimant 

 to its allocated specific title. With the exception of the gatherings made in Western 

 Australia, the examples observed or obtained on the north and eastern Australian coasts, 

 and from which the original description was drawn up, were growing in isolated colony- 

 stocks only, or, at the most, in groups of two or three contiguous polyparies on the 

 foreshore or in the reef pools of the districts named. The abundance, however, in 

 which the polyp-denuded tubes were found among the flotsam and jetsam cast upon 

 the beaches testified to its growing in considerable abundance in some less accessible 

 and probably deeper area of the sea bottom. 



The writer's later quest for this interesting type on the coasts of Western 



Australia was rewarded by its discovery in the neighbourhood of Gantheaume Point, 

 FF 



