Art. XV. — Further Descriptions of the Tertiary Polyzoa 

 of Victoria. — Part VI. 



Bv C. M. MAPLESTONE. 

 (With Plates XXXIV. and XXXV.). 



[Eead 13th December, 1900]. 



Membranipora ligulata, n. sp. (PI. XXXIV., Fig. 1). 



Zoarium erect, bilaminate, branching. Zooecia undefined, 

 margins only indicated occasionally by a slight longitudinal 

 furrow. Opesia oval, margins finely striated, raised above the 

 sui"face of the zooecia. Small oval, raised avicularia, with 

 triangular mandibular areas, scattered between the zooecia. 

 Large vicarious avicularia on margins of zoaria, with a bar ; 

 mandible triangular, acute, pointing upwards ; occasionally the 

 bar is present with a semicircular cavity below, but more often 

 the bar is broken away, making the opening appear pear-shaped 

 (inverted). 



Locality. — Aire Coastal Beds (JVlessrs. Hall and Pritchard). 



This miglit be mistaken for Hiantopora liversidgei, on account 

 of the large vicarious avicularia on the margin of the zoaria 

 being somewhat similar in shape and position to those of that 

 species, but I consider it quite distinct. The zooecia are very 

 much smaller (less than half the size), and the opesia are 

 elongated oval, not semicircular (occasionally there is a mucro 

 projecting from the side of the opesia). An examination of 

 broken specimens shows that the dorsal surfaces of these two 

 species are quite different. In //. liversidgei they are more or 

 less oval ; in tlie species now described they are very long with 

 square ends and less than half the width of those of H. liversidgei. 



It is very numerous in the deposit. In age the zooecia are 

 more calcifipd and the small avicularia are almost hidden. 



Macpopopa cribrilifera, n. sp. (PL XXXIV., Pig. 2), 



Zooecia elongated, hexagonal ; margins narrow, raised ; surface 

 granular with scattered pore-like depressions. Thyrostome 



