A MONOGRAPH OF THE TERTIARY POLYZOA OF VICTORIA. 39 



15. 31. papyracea, n.sp. PI. V., fig. 8. 



Zoarium tliin, iinilaniinate and probably encrusting. Zonecia quincuncial, 

 licxagonal but witb tbe up})or angles rounded off, separated h\ very narrow raised 

 margins ; a broad, very tliin and slightly granular lamina sloping inwards ; 

 membrane covering the aperture membrano-calcareous, but very tliin. 



B.R. 



A very delicate species, distinguished by its papery appearance. Parts of the 

 covering membrane are preserved in all the zoa^cia as an excessively thin calcareous 

 layer. 



16. 31. porfragUh, McG. PI. V., figs. 10, 11. 



Bijlnstra perfragiUs, McG., P.Z.V., 57; Membranipora id. Hincks, A.M.N. H., 

 Oct. 1884 



Zoarium bilaminate, thin. Zocecia elongated, rounded above ; aperture 

 occupying about four-fifths of the area, elliptical, its margins thickened and very 

 finely granular ; the lamina confined to the lower part of the area ; avicularia as 

 long as, but narrower than the zocecia which they replace, slightly contracted at 

 the base of the mandible, which is long, broad and directed upwards. 



M.C. A common living Australian species. 



17. 31. gregsojii, n.sp. PL V., figs. 12, 13, 14. 



Zoarium bilaminate. Zowcia large, very deep, rounded or elliptical ; margins 

 thick, rounded, finely gi'anular; avicularia small, transverse, with long setiform 

 .mandibles, situated on large bullate processes at the base of the zocecia. 



M.C; B. ; B.R. 



At once distinguished by the very peculiar avicularia. These are situated on 

 large bullate projections at the bases of the zooecia ; the basal portion is very small, 

 and there is a long narrow fissure, seemingly for the lodgment of a setiform 

 mandible, extending transversely to one side. When the front of the bullate 

 process is worn off, as is usually the case, there is left a large circumscribed cavity, 

 the real nature of which would be unintelligible without a knowledge of uninjured 

 specimens. Occasionally, in addition to the vibraculoid avicularia, there are other 

 short and broad avicularia projecting into the bases of the apertures of the zoojcia. 



I have much pleasure in dedicating this species to Mr. Gregson, to whom I am 

 indebted for the material I have examined from Bairnsdale. 



