186 Proceedings of the Royal Society of Victoria. 



Membranipopa padicifera, Hincks, sp. (PI. XXIIL, 



Fig. 7). 



I give a figure of a specimen of this species as it bears an. 

 ooecium, which is not mentioned by Dr. MacGillivray in his 

 monograph, and also for comparison with the figures of A/, bellis 

 and M. globiilosa. 



Locality. — Balcombe Bay, Mornington (T. S. Hall). 



These last three species and Al. mtermedia are closely allied, 

 but they appear to me to be specifically distinct. 



Membranipora aviculifera, n. sp. (PI. XXIIL, Fig. 8). 



Zoarium encrusting. Zooecia oval ; opesia oval, occupying 

 nearly two-thirds of area, narrow raised margins. Four spines on 

 distal border; proximal part depressed. Ooecium galeate, much 

 raised, with a subtriangular smooth depressed area in front, 

 bordered by two narrow ridges with a narrow depressed space 

 between them ; surmounted by 1'3 (?) avicularia. 



Locality. — Aire Coastal Beds (Messrs. Hall and Pritchard). 



This species, although the zooecia are not quite perfectly 

 preserved, is very distinct by reason of the ooecia being 

 surmounted by avicularia, which is a very uncommon occurrence. 

 There are three ooecia in the specimen figured (the only one 

 found), and they vary. The one on the left hand, at the top, has 

 apparently three avicularia, or, as the mandibular cavities are 

 not visible, they may be only blunt spines. The one on the 

 right hand has apparently two, although these may be, for the 

 same reason as in the other, merely spines, the depressed area 

 between the ridges on the front is triangular. Upon the third 

 one (on the right side nearer the bottom) there is a subcapitate 

 avicularium on a short stem with a triangular mandibular area. 

 The zooecium on the extreme left hand, at the top of the figure, 

 is the only one in which the opesia and margin appear to be 

 perfect; in addition to tlie four spines it bears a thick blunt one 

 protruding from below the distal margin, which appears to be 

 free, it probably was the last zooecium formed. Below the opesia 

 in most of them is a hemispherical cavity, which I think possibly 

 may be the basal wall of an ooecium, the ooecium itself being 

 broken ofi". 



