A MONOGRAPH OF THE TERTIARY POLYZOA OF VICTORIA. 9 



line, in both cases covered by the epitheca ; thyrostome large, higher than wide, 

 arched above, lower margin straight and entire, or with a sniall rounded notch or a 

 suboral pore. 



1. C. centricosa, Busk. PI. I., figs. 1, 2. 



a veutricosa. Busk, B.M.C., i., 7 ; id. C.P., Pt. I., 10 ; McG., P.Z.V. 24. 



Zocecia ovate ; fenestra; 7, pyriforni ; thyrostome with the lower margin entire 

 or with a minute notch or suboral pore ; lateral processes of moderate size, usually 

 sti-aight and produced upwards. Posterior surface convex, smooth. 



M.C; B.R. (W.) A common living Australian species. 



2. C. nobilis, n.sp. PI. I., fig. 3. 



Geminate pairs with the zocecia slightly angled at the sides ; fenesti"ate area 

 with a slightly raised margin ; fenestrse 7, pyriform ; a lateral process at each upper 

 and outer angle, supporting a large avicularium looking forwards ; thyrostome lofty, 

 rather narrow, the lower margin with a deep sinus ; a narrow raised band extending 

 upwards from behind the peristome. Posterior surface convex, smooth. Only 

 geminate zocecia seen. 



Bairnsdale. 



3. C. ampla, Waters. PI. I., figs. 4, 5, 6. 



C. ampla, Waters, Q.J.G.S., 1881, p. 317 ; id. 1883, p. 429. 



Zocecia ovate, with a distinct, raised, convex margin surrounding the fenestr^e ; 

 fenestras 7 or 9, j^yriform ; thyrostome witli the peristome raised above, straight and 

 entire below, the sides slightly contracted a little above the angles ; a short narrow 

 ridge extending upwards from the middle of the ujjper lip ; lateral processes narrow, 

 small, pointed and directed upwards. Posterior surface with a vertical depression 

 extending the whole length, and two long depressions on each side facing outwards 

 and backwards. 



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



The number of fenestra; is mostly 7, but in some specimens 9, as described by 

 Waters. These forms do not, however, otherwise differ. The thickened marginal 

 rim varies in amount of prominence, being larger in the single zocecia and in the 7- 

 fenestrated form. 



4. C. circumciiicfa, Waters. PI. I., fig. 7. 



C. circuinciiicta, Waters, Q.J.G.S., 1883, p. 432. 



Zocecia ovate, elongated ; a subraarginal row of about 1 1 round fenestrse 

 extending to each side of the thyrostome ; thyrostome witli the peristome raised 

 above, the lower margin straight and entire, and slightly wider at the angles ; a 



