BRYOZOA FROM S.W. VICTORIA, AUSTRALIA. 



331 



round pore is always seen. Aperture of peristome round ; oral aper- 

 ture, as seen from inside, apparently with a straight .proximal edge. 



The right-hand side of fig. 63 is the lower part of the zoarium, 

 being placed sideways to show the structure better. It is difficult to 

 decide if this should bo placed with Microporella or Porina. 



Loc. Fossil : Mount Gambier (Lond. Geol. Soc. coll.). 



34. Microporella yarraexsts, sp. nov. Plate XV. figs. 27, 28. 



Zoarium in Eschara-fovm, sub cylindrical, compressed ; branches 

 dividing dichotomously. Zooecium distinctly bordered, irregularly 

 oval ; peristome slightly raised. Oral aperture round on the distal 

 edge, straight on the proximal; two large pores immediately below 

 the aperture ; the upper part of the zooecium, supporting the aper- 

 ture, together with these pores, is raised ; a large protuberance on 

 one side of the zoceeium, and a smaller one on the other. In the 

 central portion of the cell a large depressed area with two or three 

 openings ; below this area a small avicularium. The zooecium is sur- 

 rounded with an indistinct row of pores. Three distal rosette-plates 

 (see fig. 28). Oral aperture 0-6 mm. wide. 



When the front of the cell is slightly worn and the aperture 

 broken down, the aperture and pores together frequently give a 

 subtriangular form to the resulting opening. 



The details could not have been deciphered from the Mount- 

 Gambier specimen, though when compared with the better-preserved 

 specimens marked Yarra-Tarra it is seen to correspond in every 

 particular. 



Loc. Mount Gambier (Lond. Geol. Soc. coll.). 



35. Microporella coscinopora, Ess., var. armata, nov. Plate XV. 

 fig. 25. 



This has a large distinct depressed cribriform area, and an avicu- 

 larium below this area ; the protuberances on the side of the zooecia 

 are wanting ; and the surface of the zooecium is flat ; the upper part 

 of the oral area is raised. Aperture 0-1 mm. wide. 



In one specimen in Miss Jelly's collection there are similar small 

 avicularia scattered irregularly over the surface. 



36. Microporella jeniomatica, sp. nov. Plate XV. figs. 29, 30. 



Zoarium in Eschara-iorm, composed of two layers back to back, 

 forming a very thin lamella, which apparently has considerable 

 extension (as all the pieces are flat and show no signs of branch- 

 ing). Surface of zooecium very flat, opening of peristome circular ; 

 opening of oral aperture, as seen from the interior, arched above, 

 straight below ; depression below the aperture, closed by a cribri- 

 form plate ; large and small acute avicularia scattered abundantly 

 over the surface. Aperture 0-1 mm. wide. 



The surface is very flat, and the openings of the oral aperture and 

 avicularia being often of nearly the same size and irregularly placed, 

 it is in some places impossible to decipher any structure. But in the 

 best-developed and best-preserved parts the peristome is seen to be 

 slightly raised ; and at first it seemed that the form of the aperture 



