A MONOGRAPH OF THE TERTIARY POLYZOA OP VICTORIA. 37 



sloping abruptly downwards and inwards, strongly granular, the granulations 

 arranged in centripetal rows ; ajDerture occupying almost the whole of the area, its 

 edges crenulated; avicularia very large, replacing zooecia, a granular and ridged 

 calcareous lamina sloping inwards, very largely developed in the mandibular portion, 

 where it occupies more than half of the cavity, much narrower in the posterior 

 portion, a stout arched calcareous bar dividing the two parts ; occasionally other 

 smaller avicularia intercalated among the zooecia. Ooecia prominent, the proximal 

 margin thickened and with a narrow raised band extending upwards. 



S.P.; M.C. 



This beautiful species is allied to M. crassimarginata (Busk), from which it 

 differs in the structure of the ooecium and especially in the mandibular part of the 

 aviculariuni, being largely filled in by the sculptured calcareous lamina. 



10. M. geminata, Waters. PL V., fig. 2. 



Membranipora geminata, Waters, Q.J.G.S., 1881, p. 325. . . 



Zoarium adnate or bilaminate and branched. Zooecia elliptical, alternate or 

 irregularly arranged ; margins raised and thick, with a series of about 20 spines ; 

 a very narrow lamina sloping abruptly inwards; aperture occupying almost the 

 whole of the area ; frequently a slight extension of the zooecium downwards below 

 the margin of the area ; avicularia (frequently absent) rounded, on the margins 

 usually below and to one side of the zooecium. At the upper extremity, inside the 

 aperture, there is a sloping calcareous plate with a depression on each side. 



S.P. ; M.C. ; B.R. ; M. ; O.C. (W.) 



11. M. depressa, n.sp. PL V., fig. 3. 

 Membranipora maorica, Waters, Q.J.G.S., 1881, p. 325. 



Zoarium usually cylindrical in Vincularia form, but occasionally broad and 

 bilaminate. Zooecia large, broad, rounded above ; margins thick and granular, with 

 a granular lamina sloping from the edges to the much depressed centre ; aperture 

 occupying about one-third of the area, rounded above, straight below, slightly 

 contracted at the sides which are granular or crenulated ; avicularia intercalated 

 among the zooecia in separate granular areas, mandible very long, pointed upwards. 



S.P.; Bel.; CO. (W.). 



This species was referred by Waters to Stoliczka's Vincularia maorica, a 

 determination with which I cannot agree. Waters himself subsequently gives 

 Stoliczka's species as identical with Escliara sexangularis (which he includes in 

 Monoporella), to which he also refers T. Wood's E. clarkei, and proposes that the 

 present form should be named var. minima or tuberculata, Q.J.Gr.S., 1885, p. 291. 



