A MONOGRAPH OP THE TERTIARY POLTZOA OF VICTORIA. 119 



Internocles with 9-17 zoojcia, the numher usually hcing niue, finely punctate. 

 Zocecia closely adnate ; thyrostome slisfhtly in'otluced and turned forwards, circular, 

 with a sharp denticle from the outer and upper edge immediately hehind the maviijin 

 of the orifice. 0«cia pyriform, on the front of the internodcs. Lateral l)ranches 

 springing from the hase of the second zooscium on one side immediately ahove the 

 thyrostome of the first. 



S.P. ; M.C. ; B.E. A common living Australian species. 



In the fossils the thyrostomcs are a good deal worn and the characteristic 

 process is consequently not usually present. In some specimens, however, it is well 

 shewn. In living specimens the joints are hlack. 



4. C. elmrnea, Linn., sp. PI. XVI., fig. 10. 



C. ehunwa, Busk, B.M.C., III., 4; Hincks, B.M.P., 420; Busk, C.P., II., 5; 

 C. margaritacea, Busk, B.M.C., III., 6. 



Internodes with 8-15 zooecia, finely punctate. Zocecia closely adnate ; thyro- 

 stome turned forwards and slightly produced, circular, entire. Branches originating 

 from the side of a zooecium, varying from the second to the fourth, immediately 

 helow the orifice. 



M.C. ; B.E. Li^dng. Europe, North America, New Zealand, Australia. 



This seems to he identical with Busk's C. margaritacea, which occurs rarely at 

 Port Phillip Heads. In the recent sjiecimens the joints are pale-cohmred, not hlack 

 as in C. acropora and C. denticnluta. The hranches are occasionally very slender. 



5. C. scalaris, n.sp. PI. XA^L, fig. 1. 



Internodes very long and slender, with upwards of twenty zooecia, the surface 

 minutely punctate ; crossed helow the thyrostomes hy small, slight, transverse 

 elevations. Zocecia' indistinct ; thyrostome circular, slightly exserted and turned 

 forwards and upwards. Dorsal surface finely punctate, crossed at intervals hy small 

 transverse elevations similar to those in front. Branches originating hy a very wide 

 articulation from the side of a zocecium. 



C.B. 



6. C. sefosa, McG. PI. XVI., figs. 6, 11. 



C. sefosa, McG., P.Z.V., 39. 



Branches very slender. Internodes, with 4-10 zocecia, finely punctate. Zooecia 

 very slender, distinct, closely adnate ; peristome produced, turned forwards and out- 

 Avarcls heyond the edge of the internode; thyrostome circular, with a long hollow 



