40 A MONOGRAPH OF THE TERTIARY POLTZOA OP VICTORIA. 



18. M. fossa, n.sp.. PL V., fig. 16. 



Zoarium bilaminate, thick. Zooecia indistinct, narrow elliptical, with thick 

 granular walls ; aperture occupying quite or nearly the whole area, contracted at 

 the junction of the upper and second fourths. 



W.P. 



The specimens are not in a very good state of preservation, but it seems distinct 

 from any described species. The walls of the zooecia are continuous, flat and finely 

 granular, and the separating line can only be defined with difficulty. The aperture 

 (corresponding to nearly the whole area) looks as if punched out of a thick 

 calcareous layer. 



19. M. cochleare, n.sp. PI. V., figs. 17, 18. 



Of this I have only two single zooecia. The upper portion is much enlarged, 

 ovate or rounded, with a thick margin within the base of which is, in one specimen, 

 a broad internal plate ; the lower part of the zoarium is narrow, flat or depressed and 

 much prolonged. 



S.P.; M. 



The zoarium has probably been bilaminate. The inferior plate is of the same 

 nature as the denticle or plate found in some specimens of M. delicatula. 



20. M. ambigua, n.sp. PL VI., fig. 12. 



Zoarium bilaminate. Zooecia elongated, somewhat quadrate or nearly hexagonal; 

 margins thick, raised, strongly granular, abruptly sloping to the equally granular 

 lamina, which is very much depressed anteriorly, where it ends in a broad, nearly 

 quadrate, slightly upturned prolongation or plate with a distinctly thickened rim ; 

 aperture occupying about a third or a fourth part of the area and reaching on each 

 side to the margin ; avicularia intercalated among the zooecia, anterior extremity 

 pointed and raised, the sides granular and sloping to an elongated opening. 



S.P. 



21. M. bidens, Busk, sp. PL VI., fig. 13. 



Membranipora bidens, Busk, Crag Polyzoa, p. 34 ; Micropora hippocrepis, 

 Waters, Q.J.G.8., 1882, p. 264. 



Zoarium bilaminate. Zooecia alternate in regular linear series, quadrate, 

 elongated ; margins thick, granular ; lamina depressed, granular ; aperture at the 

 extreme upper end of the zocecium, shallow, the lower edge turned forwards as a 

 broad denticle or plate, usually slightly hollowed in the middle and with the margin 

 slightly thickened. 



