A MONOGRAPH OF THE TERTIARY POLYZOA OF VICTORIA. 61 



This family group has already been suggested by Hincks (A.M.N.H., Deceml)er, 

 1891) in a valuable criticism on Cribrilina monoceros and ILiantopora ferox, in 

 which he points out the relationshij) of these two species and the real developmental 

 structure of the perforated front Avail. Jullien (Cap Horn Bryozoaires, p. 62) 

 places C monoceros under a distinct genus — AraclniopHsia — of which he makes a 

 separate family. The characters on Avliich he founds both family and genus are, as 

 Hincks remarks, only of secondary importance, and at the most of merely specific 

 value. 



II. monoceros differs from II. ferox in having the zooecia in their early 

 membraniporidau state closely united and not disjunct and joined by comniuni- 

 cating tubes as in the last named species and probably in U. ludli. This junction 

 of the early zocecia by membranous tubes is similar to the arrangement in many 

 species of Beania (Diachoris) and several species of membranipora, and the attach- 

 ment by posterior radical tubes shews a farther alliance to 31. radlcifera. 



Hianto2)ora, McG. 

 Characters as for the family. 



1. //. //(ill/-, n.sp. PI. VIII., tig. 25. 



Zooecia indistinct, alternate, very deep ; front Avail covered by a calcareous plate 

 with large elliptical or ovate perforations, the anterior edge being entire, sharply 

 turned forwards, and surmounted by a pair of slight eminences with small depres- 

 sions (seemingly aAdcularian) on their summits ; the base of the zoojcium behind 

 the perforated plate, smooth, with a transverse reuiform pore, from Avhich descends 

 a short, sharp ridge ; a large raised avicularium, Avith long mandible, extending 

 ou.twards from each side opposite the reniform pore to the elevation of the retiform 

 plate of the contiguous zoa^cium ; anterior part of the zooecium much depressed ; 

 thyrostome having a auinute avicularium above its straight upper edge, and a stout 

 rigid calcareous spine on each side. Ooecium mitriform, immersed. Dorsally the 

 inferior portion of the zoceciura much projecting, Avith numerous small conical 

 elevations, ending in calcareous radical tubes. 



M.C. 



Unfortunately the only specimen I have seen does not shoAv the zooecial growth 

 satisfactorily, the marginal zooecia being Avell calcified. So far as I can make out, 

 the inferior reniform pore is formed by the junction of a small plate from each 

 margin ; from the upper of these j^lates tAvo or three processes groAv forAvards and 

 anastomose to form the perforated front Avail ; the elevated anterior bar seems to be 

 constituted by a growth from the bases of the avicularia of the contiguous zooecia. 



