22 Proceedings of the Royal Society of Victoria. 



pore below it. One or two small elliptical avicularia on the- 

 surface, with a denticle on each side. 



Locality. — Mitchell River (J. Dennant). 



A single specimen not very well preserved (the front wall is 

 apparently broken away in places) but easily distinguished by the 

 shape of the thyrostome and avicularia. The ridges on the sur- 

 face are very irregular, and do not appear to indicate the margins 

 of the zooecia. The small pore below the proximal margin of the- 

 thyrostome would seem to place this in Porina, but I do not 

 think it extends through the cell-wall. 



Mucronella airensis, n. sp. (PI. II., Fig. 12). 



Zoaria ligulate, with zooecia on both sides. Zooecia irregular 

 in shape, raised towards the distal end; surface finely granulated. 

 Thyrostome orbicular, with a raised peristome ; a very small 

 mucro in the proximal part of the margin. A small, elongated, 

 avicularium on the side of the raised peristome; also several 

 small broadly-oval ones scattered over the surface. 



Locality. — Aire Coastal Beds (T. S. Hall). 



The elevation of the peristome, and the surrounding portion of 

 the surface is very marked; the small, oval avicularia have half 

 the area covered. 



Mucronella personata, n. sp. (PI. II., Pig. 13). 



Zoarium encrusting. Zooecia elongate, quadrate, with a single 

 or double row of pores round the margin ; margin slightly raised. 

 Thyrostome suborbicular or unguiform, with a curved flat mucro 

 in the proximal margin; peristome narrow, raised; a small, oval 

 avicularium on each side of the thyrostome. Ooecia orbicular, 

 immersed, smooth, with a rounded, shallow pit in front of each 

 side of a slightly-raised carina. 



Locality. — Aire River (A. E. Kitson), 



This is a very well-marked species ; the mucro is a simple 

 curved extension of the wall of the zooecium, and were it not 

 so prominent it would probably be, considered to be a Lepralia. 

 The dorsal surface has a round perforation near the distal end,, 

 which is visible through the opening of the thyrostome. 



