Zoology.] NATURAL HISTORY OF VICTORIA. [Polyzoa. 



Plate 147, Fig. 5. 



DIASTOPORA PATINA (Lamarck, sp.). 



Description. — Zoarium small, thin, usually more or less circular or elliptical, 

 surrounded by an extension of the basal lamina. Zocecia stout, thickly punctate, 

 crowded, more immersed towards the centre, in more or less radiating- lines towards 

 the circumference and usually open ; orifice in the central zocecia elliptical or 

 round and frequently closed by a minutely perforated calcareous plate, in those 

 towards the margin elliptical or produced on one side. Ocecium a large inflation of 

 the zoarium. 



Reference. — Hincks, Brit. Mar. Poly., p. i5S, pi. lxvi., figs. 1-6. 



Port Phillip Heads. 



The specimens I have examined of this species are all small, 

 silvery and encrusting. In Europe, where it is abundant, it seems 

 to vary very much, being sometimes caliculate and partly free, and 

 occasionally proliferous at the margins. A full account of these 

 forms is given by Mr. Hincks. 



Explanation or Figures. 



Plate 147. — Fig. 5, specimen, natural size. Fig. 5a, portion of same magnified, showing 

 two central zooecia closed by perforated plates and an oceciuni. 



The specimens and descriptions of our Diastoporce on this plate 

 I owe to Mr. MacGillivray. 



Frederick McCoy. 



[ 182 J 



