92 A MONOGRAPH OF THE TERTIARY POLYZOA OP VICTORIA. 



thyrostome subcircular by the development of the peristome contracted downwards, 

 with a squared denticle in the lower lip ; several spines on the upper margin ; a 

 small avicularium in front of the denticle, on the upper part of a bullate projection 

 occupying the portion of the zooeciuni immediately below tbe thyrostome. Ocecia 

 small, globular, smooth, with faint radiating lines. 



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



5. P. innocua, n.sp. PL XII., fig. 13. 



Zooecia elongated, separated by narrow raised lines, with a row of long, narrow, 

 deep areolae along the margins, sometimes almost meeting in centre ; thyrostome 

 large, elongated, subquadrate, but rounded above, with a very large, deep, squared 

 median denticle and a small acute one on each side ; a small avicularium in the 

 lower lip of the peristome. Ooecia small, depressed, punctured. 



B.; M. 



Smittia, Hincks. 



Thyrostome semicircular, with a square denticle (lyrula) in the lower margin ; 

 secondary aperture elongated, the peristome raised on the sides and forming a spout- 

 like channel below, in which is usually lodged an avicularium. 



1. S. transversa, n.sp. PL XII., fig. 14. 



Zoarium bilaminate. Zooecia quadrate or hexagonal, separated by narrow 

 raised lines, nearly flat, granular, especially in a line immediately within the 

 margin, and with numerous small round perforations ; thyrostome lofty, arched 

 above, contracted below, with a deep rounded sinus in the lower lip formed by the 

 projection of a denticle on each side ; a broadly linear avicularium situated trans- 

 versely immediately below the thyrostome. Ooscium large, convex, occupying 

 greater part of the zocecium on which it is placed, granular and punctured. 



B.E. 



2. S. depressa, n.sp. PL XII., fig. 15. 



Zooecia large, ovate; margins much thickened and raised, the junction of 

 those of contiguous zooecia indicated by a faint line ; surface depressed, flat, with 

 numerous large pores ; thyrostome large, lofty, arched above, with a deep sinus, 

 which is narrowed above and rounded at its extremity. 



M.C; B. 



When the front wall is examined from behind, a small pointed median denticle 

 is seen. 



