Zoology.-] NATURAL HISTORY OF VICTORIA. \Po\yzoa. 



Plate 147, Fig. 1. 



DIASTOPORA CRIST AT A (McG.). 



[Genus DIASTOPORA (Johnston). (Sub-kingdom Mollusca. Class Polyzoa. Order 



Infundibulata. Sub-order Cheilostomata. Family Tubuliporidae.) 



Gen. Char. — Zoarium adnate, discoid or flabelliform, or wholly or partly raised and 

 bilaminate. Zooecia tubular, with an elliptical or sub-circular orifice, crowded and immersed 

 towards the centre, more distinct and partially free towards the margins.] 



Description. — Zoarium either encrusting and with portions raised into 

 bilaminate lobes, or wholly bilaminate, the laminee parted by a thin calcareous 

 septum, the margin of which is produced beyond the zocecia to form a crest-like 

 ridg-e. Zocecia crowded, free for a considerable extent; immersed portions separated 

 by shallow grooves ; surface finely and closely punctate, except the free part which 

 is smooth or obscurely ringed; mouth circular or oblique. Ocecium a large inflation 

 of the zoarium. 



Reference. — P. H. MacGillivray, Trans. Roy. Soc. Vict., March 1886. 



Port Phillip Heads, Mr. J. Bracebridge Wilson. 



In some specimens, as that figured of the natural size, the 

 greater part of the zoarium is bilaminate, the lobes being large and 

 only a small part encrusting. In others, as in that from which the 

 magnified figures were drawn, the zoarium is mostly encrusting, 

 frequently surrounding the calcareous tubes of annelids, and in 

 parts rising into small bilaminate lobes. In the encrusting parts 

 a thin, basal, calcareous membrane frequently extends beyond the 

 zocecia, and a similar membrane separates the layers of the 

 bilaminate lobes. The zooecia vary a good deal in size, in some 

 parts being almost wholly immersed, while in others the free part 

 is long and tubular. 



In the Proceedings of the Linnean Society of New South Wales 

 for 1881, is a contribution by Mr. Haswell, describing a species 

 as Mesenteripora repens which may be identical with this, but 

 there is no figure, and the description is scarcely sufficient for 

 identification. 



Explanation of Figures. 



Plate 147. — Fig. 1, bilaminate specimen, natural size. Fig. la, one surface of a lobe from 

 another specimen, showing the extension of the calcareous septum. Fig. \b, another portion of 

 the same, showing an encrusting portion, a bilaminate lobe, and an ooecium. 



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