146 Proceedings of the Royal Society of Victoria. 



nevertheless, there is one new form which I now describe, 

 because it is a very elegant and striking one. 



Hopnera airensis, n. sp. (PL XVII., Fig. 13 and I3a). 



Zoarium dendroid, dichotomously branched, branches circular 

 in section, growing on one side only ("?), at an acute angle, and 

 parallel to one another, causing tlie zoaria to assume a pinnate 

 form, zooecia undefined, in a double row, apertures alternating ; 

 front surface with lai-ge oval perforations. Orifice circular ; peri, 

 stomes raised. Dorsal surface with oval pores in very regular 

 parallel lines. 



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



This is a most elegant species ; it is generally found very frag- 

 mentary, but in one lump of clay there was a specimen with 

 several branches, which unfortunately broke up in the cleansing 

 process. 



This species in some measure shows the difficulty above alluded 

 to, that there is in dealing with the Cyclostomata at present. 

 The regularity of the disposition of the zooecial apertures would 

 place it in Idmonea according to the older authorities ; though as 

 it is " free " (not encrusting or adherent) it would be placed by 

 some later ones in Crisina ; but as the walls of the zooecia are 

 perforated in the same manner as those of Hornera I place it in 

 that genus and would associate with it Idmonea hochstetteriana, 

 Stol. The family Horneridae, to which this last genus (Horn- 

 era) belongs, Dr. Gregory, in his Catalogue of the Cretaceous 

 Bryozoa in the British Museum, includes in a new sub-order 

 Cancellata, which removes this genus far away from Idmonea. 



EXPLANATION OF PLATES XVI., XVII. 



Fig. 1. — Dimorphocella pyriformis, n. sp. 



,, 2. — Dimorphocella triton, McG. 



„ 3. — Phylactella cribrosa, n. sp. 



,, 4. — Schismopora circumvallata, n. sp. 



