190 Mr. A. W. Waters on Australian Bryozoa. 



so unsatisfactory that the species intended was left somewhat 

 doubtful ; but as Milne-Edwards described it in more detail it 

 is perhaps a question whether we ought not to call it gracilis^ 

 Lamx. & Edw. 



As I have already pointed out, the opercula of species grow- 

 ing in the h or vertebralis-f OYm^ although slightly smaller, 

 correspond with those from typical ^^ Eschara gracilis'''' 

 growing in a foliaceous manner. 



Loc. Fossil : France (Cretaceous) ; Miocene of Europe ; 

 Australia ; New Zealand, various localities. Living : in 

 Z)-form, Holborn Island, 20 fath. ; Darnley Island, Torres 

 Straits, 10-30 fath. ; Cape Grenville, N.E. Australia, 

 20 fath. 



46. Porina inversa, sp. no v. 

 (PL IV. fig. 23 ; PI. V. fig. 5.) 



Zoarium incrusting. Zooecia indistinct, surface flat with 

 large pores ; a perforated protuberance, probably avicularium, 

 at each side of the aperture 5 a round suboral pore. The oral 

 aperture is straight on the distal edge and rounded on the 

 proximal^ with the operculum divided radially by irregular 

 bars of thicker chitin, and an irregular ridge near the distal 

 edge. It will be seen that the shape of the oral aperture, 

 which is directed more or less towards the distal part of the 

 zoarium, is the reverse of the usual shape of Porina, and, in 

 fact, of the Bryozoa generally, so that, being peculiar in this 

 respect, it is a question whether a new genus should not be 

 made for it. 



The zooecial characters seem much the same as those of 

 Myriozoum marionensis , Busk (Chall. Eep. p. 171, pi. xxiii. 

 fig. 6), and there are two figures (pi. ex. figs. 2, 3) in Busk 

 (Brit. Mar. Polyzoa) which seem to be without any descrip- 

 tion, and may be allied to the present. 



Loc. Sow-and-Pigs Eeef, 3-4 fath., and Port Jackson, 

 10 fath. 



47. Tubucellaria opuntioides, Pall. 

 (PI. V. fig. 10.) 



Cellaria opuntioides, Pergens, Plioc. Bry. von Rhodos, p. 12. 

 Tubucellaria cereoides, MacG. Zool. Vict. dec. xi. p. 18, pi. 105. fig. 2. 



There are small fragments from Bondi Bay and Adelaide 

 which have the peristome very much prolonged and then 

 curved inwards. This occurs in the Mediterranean T. opun- 

 tioides {cereoides) and in T. hirsuta, and in this last the 

 position of the spines remains constant in relation to the pores 

 and not to the aperture. The prolonged peristome was figured 



