112 



frontal surface, and with a calcified, rugged ectoocecium. On each side of the 

 ooecium is a small obliquely placed spine. 



I have been able to examine a colony of this species from Port Phillip, Vic- 

 toria (Miss Jelly). 



To the genus Hiantopora, which Mac Gillivray has founded on y>Cribrilina'^ 

 ferox, I must, besides this species, also refer Membranipora radicifera as well as 

 the form which Kirkpa trick has described under the name M. radicifera, v. 

 intermedia, and which he considers as an intermediate form between H. ferox 

 and H. radicifera. I agree with this writer as to the necessity of referring all three 

 forms to the same genus; but whilst he refers them to Membranipora, I must, partly 

 on account of their points of agreement with Beania, partly because of the free 

 ooecia, refer them to the family Bicellariidae, and although they must come close 

 to Beania, they cannot for several reasons be included under this genus. Some 

 of these reasons are: the strong calcification, the presence of ooecia, which however 

 have hitherto only been found in H. radicifera, and finally the presence of the 

 sessile avicularia (in contrast to the pedicellate movable ones in Beania). Lastly 

 this avicularium is in all three species furnished with a spine, which in each 

 attains an extremely variable development, and in H. ferox covers the greater 

 part of the frontal surface with its branches, and this is the reason why this 

 species was formerly referred to the genus Cribrilina. In H. radicifera it is rather 

 small undivided, conical, whilst it is much larger and richly branched in H. 

 intermedia, but in contrast to the spine in H. ferox it pi-ojects freely here. Of 

 H. ferox besides Kirkpatrick's original specimens I have been able to examine 

 two others, namely one from Port Phillip (Miss Jelly) and another from Port 

 Phillip Heads (Mr. J. Gabriel); they show all differences in the shape and 

 development of the avicularian spine, so that the species seems to undergo great 

 variation. It may be possible to set up several different species. All three species 

 agree however in that this hollow avicularian spine which may in reality be 

 looked upon as a hollow, branched continuation of the avicularian chamber, is 

 not, as Kirkpatrick seems to believe, connected with the ojiposite margin of 

 the respective zooecium, but mainly with parts of the surrounding zooecia, partly 

 with their distal spine or distal margin, partly with their avicularia or with the 

 branched prolongations of these. The tip of the avicularian spine is however 

 often fused together with a small branched spine, which arises from the distal 

 half of the opposite margin of the zooecium. 



Mac Gillivray', who originally referred the genus Hiantopora to the family 



' 75, p. 22. 



