A MONOGRAPH OF THE TERTIARY POLTZOA OP VICTORIA. 113 



vertical fissure extending its whole length, forming a large prominence on each side, 

 with the inner margin turned backwards especially towards the base of the sinus ; 

 the peristome frequently surrounded by a narrow raised line. A small avicularium 

 below the thyrostome with the broad mandible pointed downwards, and below that 

 a small pore (both frequently absent). Dorsal surface divided into areas, angular 

 above and below, separated by narrow raised vibices, smooth, with numerous small 

 nodular elevations and a few small pores ; scattered immersed elliptical avicularia, 

 with the mandible expanded and sometimes almost spatulate. 



S.P. ; M.C. ; B. ; C.B. 



Distinguished by the lofty peristome bulging on each side of the median 

 fissure, and by the elongated noduliferous areas on the back of the zoarium. 



5. R. avicularis, McGr. 



B. avicularis, McG., T.R.S.V., 1882 ; P.Z.V., 94, 95. 



Zoarium fenestrate ; fenestras elongated, wider than the narrow trabecule. 

 Zooecia ovate, separated by narrow raised margins ; thyrostome with a small sinus 

 in the lower lip, the angles on each side of the sinus produced into a sharp point ; 

 on the front of the zooecium a large bullate elevation supporting an avicularium, 

 and frequently a small elliptical avicularium to one side ; several small pores on the 

 front of the zooecia. Dorsal surface strongly vibicate, with a few avicularia. 



S.P. Recent Victoria. 



I have only a single specimen, which seems referable to It. avicularis. In the 

 recent specimens there is a long spine on each side of the thyrostome. In the fossil 

 the processes on the sides of the sinus are not so distinct and the spines are only 

 shewn on one or two of the zooecia. In the recent form there are no anterior 

 avicularia except those on the bullate elevations. There are no ocecia in the fossil 

 specimen, in the recent they are rounded and entire. I have little doubt, however, 

 of the identification. 



6. R. schnapperensis, n.sp. PL XV., fig. 6. 



Zoarium fenestrate. Zooecia wider in the middle, separated by prominent 

 raised lines ; thyrostome nearly circular, with a small rounded notch in the lower 

 lip, and two or three spines (usually absent) above ; peristome thickened all round, 

 more produced at the sides ; an avicularium about the middle of the zooecium. 

 Dorsal surface smooth, with raised vibices; an avicularium usually towards the 

 inferior part of each area. 



S.P.; B. 



Q 



