12 A MONOGRAPH OF THE TERTIARY POLYZOA OF VICTORIA. 



with very large supra- and infra-avicularian chambers or depressions ; occasionally a 

 second (pedal) chamber below the last. Posterior surface convex or carinate. 

 S.P. ; M.C. ; B. A living Australian sjsecies. 



11. C. crux, n.sp. PI. I., fig. 18. 



Zooecium nearly quadrate, narrowed above and with a long narrow prolongation 

 below; a depressed area with six small fenestras; thyrostome small, straight or 

 slightly hollowed and entire below, and with a minute denticle on each side ; a long, 

 narrow avicularian chamber on each side, supporting a minute avicularium ; a large 

 supra- and a rather smaller infra-avicularian chamber; a long, narrow depression 

 on each side of the inferior stem-like prolongation. Posteriorly, the inferior 

 prolongation sharply convex, the convexity ending above in a prominent umbo. 



S.P. ; M.C. 



Allied to the recent C. carinata and also to C. (data and elongata. 



12. C. porosa, n.sp. PI. I., fig. 19. 



Of this I have only the single fragment figured, so that a full description is 

 impossible. I have no doubt, however, that it is a good species. It presents an 

 unusual arrangement in the true Catenicellas in the ocecium being fixed on the front 

 of a cell in a series instead of being terminal. The ordinary thyrostome is small, 

 arched above, slightly hollowed and entire below, and with a minute denticle on 

 each side. The aperture of the fertile zooecium and ocecium is very wide, semilunar, 

 the angles very sharp, and the lower margin with a large rounded sinus. There are 

 several fenestras on the front of the zooecium of which enough, however, is not 

 preserved to show their number and arrangement ; and at the side immediately 

 below the thyrostome there seems to have been a large anterior avicularium. The 

 ocecium is large, nearly flat and slightly prominent, surrounded by a thick, raised, 

 smooth band enclosing a nearly circular, minutely-perforated area. The posterior 

 surface is rounded and smooth. 



M.C. 



13. 0. cribraria, Busk. PI. I., fig. 20. 



C. cribraria, Busk, B.M.C., P. I., 9 ; id. C.P., p. 11 ; McG., P.Z.V., 24. 



Zooecia broadly ovate ; lateral processes of moderate size, with an avicularium 

 opening outwards ; anterior surface convex with an outer row of moderate-sized 

 elliptical fenestras and numerous smaller internal ones ; thyrostome large, lower 

 margin slightly convex upwards. Posterior surface smooth. 



S.P. ; M.C. ; B. ; M. Living, Australia. 



