188 Proceedings of tJie Royal Society of Victoria. 



Membranipor'a popcellana, n. sp. (PI. XXIV., Fig. 11). 



Zoarium unilaminate, but folded. Zooecia indistinct ; opesia 

 oval and circular, with narrow raised smooth margins ; surface 

 smooth porcellaneous. Avicularia hour-glass shaped, vicarious. 



Zoca /i^y. —Clihon Bank, Muddy Creek (T. S. Hall). 



This is a very distinct form. The zoarium is unilaminate, 

 apparently cylindrical, but it is coiled round an imaginary axis ; 

 the opesia of the inner coil can be seen through those of the outer 

 one. The zooecia are undefined, and the opesia occupy almost 

 the whole of the area. The avicularia are hour-glass shaped and 

 vicarious. 



Amphiblestpum planulatum, n. sp. (PI. XXIV., Fig. 12). 



Zoarium bilaminate, ligulate. Zooecia elongated, distal portion 

 oval, proximal quadrangular, with a narrow raised border ; opesia 

 oval, with finely granulated raised margins. Avicularia, two 

 below opesia, one above, occasionally one or two others on the 

 quadrangular area. Ooecia galeate, with flattened area in front. 



Localitv. — Aire Coastal Beds (Messrs. Hall and Pritchard). 



This is very plentiful in the deposit, and varies considerably in 

 the shape of the zooecia, owing to the flat quadrangular area 

 being in some cases reduced to a very small space. 



Amphiblestrum vafiabile, n. sp. (PI. XXIA'., Fig. 13). 



Zoarium encrusting. Zooecia irregularly disposed, oval or 

 pyriform, surface smooth ; opesia oval, occupying nearly two- 

 thirds of the area, surrounded by a row of about 20 spines. A 

 small avicularium below, immersed, with oval transverse mandible. 

 Ooecium (?) irregular in .shape, with an irregular opening. 



Locality. — Lower beds. Muddy Creek (J. Dennant). 



This species somewhat resembles j\Ieinbranipora geininata, 

 AVaters, but the extension of the zooecia below the opesia and 

 the avicularium .show it to be different. I take the irregular cell 

 with the elongated opening to be an ooecium, as it differs from 

 the zooecia in the margin being smooth, without any spines, and 

 it has no avicularium. 



