Descriptions of JS T ew, or Little Known, Polyzoa. 117 



Mr. Maplestone. Ifc is distinguished by the polished, 

 glistening surface of the cells, usually destitute of any 

 marks, but occasionally showing a few small puncta. 

 Sometimes a few cells in a series are united side to side, 

 and in that case the orifices of the peristome are somewhat 

 prismatic. 



Diastopora bicolor, n. sp. Plate V., fig. 2. 



Zoarium nearly circular, consisting of three parts : Ta 

 central elevated portion composed of perfect cells, sur- 

 rounded by a broad fringe of imperfectly developed cells, 

 beyond which is a thin lamina ; the central portion is red, 

 the remainder glassy. The central portion is much raised, 

 fiat and depressed at the centre. The cells are arranged in 

 irregular, radiating series ; the series are distinct, but with- 

 out intervening spaces. The cells are slightly rugose and 

 thickly punctate. The mouth is oval or elliptical, with 

 slightly thickened margin ; those of the marginal cells are 

 open, most of the inner being filled in by a plate punctate 

 or perforated like the rest of the cell. In the central part are 

 numerous rounded eminences, mostly at the commencement 

 of the series of cells, and of the same width ; they are punc- 

 tate or perforated in the same manner,, but present no trace 

 of mouth. The surrounding fringe consists of a broad layer 

 of imperfectly developed cells ; the thin lamina beyond this 

 is marked with slight, radiating grooves, as occurs in the 

 corresponding part of other species of Diastopora and Disco- 

 porella. 



Port Phillip Heads, Mr. J. B. Wilson. 



