Zoology.] NATURAL HISTORY OF VICTORIA. [l'ol,,zoa. 



Pyripora forme a very natural genus, and was first proposed by 

 D'Orbigny, but its species have generally been included in Hippo- 

 thoa, with which it has no real connection, or in Membranipora. 

 The chief distinction from the other Membraniporidse consists in 

 the zocecia being very calcareous, thick, convex, much narrowed 

 below, and not separated by raised margins. The habit also is to 

 run in irregular, branching series. 



Plate 10G-, Fig. 5. 

 PYRIPORA CATENULARIA (Jameson). 



Description. — Zocecia elongated, wide above, much narrowed below, arranged 

 in linear or branching- series, or occasionally aggregated ; surface smooth or 

 annotated; aperture oval or elliptical, occupying greater part of the expanded 

 portion ; margin flattened or bevelled, especially below. 



References. — Hippothoa calenularia, Busk, Cat. Mar. Pol. Brit. Mus., pt. i., 

 p. 09, pi. xviii., figs. 1,2; Membranipora catenularia, Hincks, Brit. Mar. Pol., 

 p. 134, pi. xvii., figs. 1, 2. 



Port Phillip Heads ; Brighton. 



I can detect no difference between this and the common 

 European form. In my specimens the bevelled margin of the 

 aperture is frequently granular. 



Explanation of Figuke. 

 Plate 106. — Fig. 5, portion of a specimen in branching series, magnified. 



Plate 10G, Fig. 6. 



PYRIPORA POLITA (Hincks). 



Description. — Zocecia very porcellanous, usually close together, narrowed 

 downwards; aperture occupying about a third or more of the front; below the 

 aperture a rounded or oval protuberance and on each side an oval or elliptical mass; 

 sometimes these convexities are not distinctly marked, and there is occasionally a 

 thickened collar all round the aperture, and there are sometimes several transverse 

 markings across the front of the zooecium. 



Reference. — Membranipora polita, Hincks, Ann. and Mag. Nat. Hist., Nov. 

 1880. 



Queenscliff, on Cymodocea antarctica. 



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