42 A MONOGRAPH OF THE TERTIARY POLTZOA OP VICTORIA. 



Zoarium in narrow, flat, bilaminate branches. Zooecia quincuncial, separated 

 by raised margins, elongated, hexagonal ; aperture occupying about half the area, 

 not quite reaching the margins of the zooeciura, with a slightly thickened and raised 

 rim ; lamina calcareous, finely granular. 



M.C. ; B.E, ; W.P. (W.) 



4. A. coriense, n.sp. PI. VI., fig. 1. 



Zoarium unilaminate. Zooecia large, regularly arranged alternately in longi- 

 tudinal series, hexagonal ; margins raised, finely granular ; aperture occupying 

 about half the area, trifoliate; lamina minutely granular, sloping. Avicularia very 

 large, situated between the zooecia, lower part finely granular, with a longitudinal 

 narrow opening, mandibular portion very long, curved and scimitar-shaped, being 

 obliquely truncated at the extremity. Ooecia prominent, rounded, finely granular, 

 thickened at the inferior edge, esjoecially in the middle. Zooecia posteriorly distinct, 

 enlarged above, narrowed below, with a large circular mark (probably indicating 

 the attachment of a radical fibre) in the centre of each. 



C.B. 



Allied to A. flemingii and A. trifolinm. The only avicularium present in the 

 specimen is that figured. In one or two only of the zooecia, all of which are 

 surmounted by ooecia, there are indications of a spine at an upper angle. 



5. A. permimitum, Hincks, sp. PI. V., fig. 19. 



Membranipora permunita, Hincks, A.M.N.H., 1881 ; Amphiblestmm per-^ 

 mnnitum, McG., P.Z.V., 106 ; M. michmidiana, Waters, Q. J.Gr.S., Aug., 1885, 

 p. 289. 



Zoarium encrusting. Zooecia elongated, wider at the middle ; margin raised, 

 granular; a finely granular lamina sloping anteriorly to the aperture, which 

 occupies about a third of the area and has a straight lower border ; avicularia at the 

 base of aborted zooecia, with a falciform mandible directed upwards and to one side. 

 Ooecia small, prominent, rounded, a semicircular or triangular sjDace in front marked 

 off by a slightly raised band, the upper angle of which frequently projects forward 

 as a point. 



M.C. Living. Australia. 



Waters refers this species to D'Orbigny's Collepora michandiana, a determina- 

 tion which seems to me at least doubtful, and I, therefore, retain the name by 

 which the recent form is known. 



