66 A MONOGRAPH OF THE TERTIARY POLTZOA OP VICTORIA. 



contracted below, peristome thickened and projecting, granulo-punctate like the 

 surface. 



S.P., a single zocecium. 



Tessaradoma, Norman. 



Zoarinrn encrusting or foliaceous and unilaminate, or erect and ramose. 

 Zooecia with the peristome produced and turned forwards in a tubular or subtubular 

 manner; a median tubular zooecial pore (trypa). 



The genus Tessaradoma was originally proposed by Norman for Busk's 

 Onchopora borealis, a species subsequently included, as well as T. magnirostris, 

 by Hincks in Porina. I have already (C.V.) proposed that those species agreeing 

 with Porina in other respects but differing in the anterior pore opening directly 

 into the body cavity should be included in Tessaradoma, while those in which the 

 pore is external or peristomial should be referred to Porina. 



1. T. magnirostris, McGr. PL IX., fig. 19. 



Zepralia magnirostris, McGr., T.R.S.V., Oct. 1882; Tessaradoma, id., McGr., 

 P.Z.V. 175; Porina magnirostris, Hincks, A.M.N. H, Oct. 1881; Microporella 

 introversa, Waters, Q.J.G.S., 1882, p. 268. 



Zooecia indistinct ; surface with numerous large rounded pores, excej)t in the 

 neighbourhood of the thyrostome ; thyrostome arched above, nearly straight below ; 

 peristome thickened and raised ; a large sessile avicularium on one or both sides of 

 the zocecium about the middle, with the triangular mandible directed straight 

 outwards and encroaching on the adjacent zocecium. 



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



2. T. elevata, Waters, sp. PL IX., fig. 28. 



? Escliara elevata, Tenison Woods, T.R.S. N.S.W., 1876, p. 148 ; Hicroporella 

 elevata, Waters, Q.J.G.S., 1881, p. 330. 



Zoarium expanded, or lobed and bilaminate, or cylindrical, traversed by 

 numerous anastomosing sharply raised ridges, inclosing angular depressed spaces 

 in which are several irregularly shaped pores; usually one of these ridges 

 surrounding the thyrostome; thyrostome (secondary) with the peristome thick, 

 tubular and directed vertically forwards ; usually several pores round the base of 

 the peristome and opening into its chamber ; a zocecial pore (not always distinguish- 

 able externally from the other pores) some distance below the thyrostome ; numerous 

 rounded avicularia, with the mandibular transverse bar well marked at the anas- 



