276 G. M. Maplestone: 



A single specimen, consisting of five zooecia ; it differs from 

 C. halcomiensis in the distal part of the zooecia, being directed 

 alternately outwards, and in the presence of avicularia. 



Membpanipopa laevissima, n. sp. (PI. XLI., Fig. 26). 



Zoarium encrusting. Zooecia undefined, slightly calcified, 

 very shallow ; aperture oval, with smooth margins ; interspaces 

 only slightly raised, smooth, with small oval avicularia between 

 the zooecia. 



Locality. — Wilkinson's No. i (Dr. Hall). 



A single specimen growing on a fragment of a bivalve shell. 

 It is very flat and thin looking, more like a thin gelatinous film 

 than a calcified structure, the surface of the shell is exposed in 

 the apertures, and there is no trace of any basal wall, which 

 was probably membranous. 



Membranipopa ovifepa, n. sp. (PI. XLII., Fig. 27). 



Zoarium encrusting. Zooecia irregularly oval, in transverse 

 rows; aperture large; margins raised, flat; scattered vicarious 

 oviform avicularia, with oval mandibular area. 



Locality. — Orphanage Hill, Geelong (Dr. Hall). 



This in appearance resembles some specimens of M. gregsoni, 

 McG., but the form of the avicularia is very different ; all, except 

 one, of the apertures are filled with fine particles of sand, and it 

 is interesting to note that one of the zooecia is regenerated, the 

 margin of the later formed one showing within that of the older. 



Steganoporella dennanti, n. sp. (PI. XLIIL, Fig. 28). 



Zoarium in vincularian form. Zooecia dimorphic, elongated, 

 arched and overlapping distally. Cryptocyst depressed, occupy- 

 ing about half the length of the zooecia, perforated with very 

 small pores ; a rounded opesiule on each side at the distal end ; 

 median process straight ; oral shelf forming a subtriangular 

 or coi'date arch. In the " B " zooecia the polypide tube descends 

 distally to the basal floor. 



"A" zooecia L2 mm. long, 0.4 to 0.6 mm. wide. 



" B "' zooecia 1.3 mm. long:, 0.7 to 0.8 mm. wide. 



