Mr. A. W. Waters on Australian Bryozoa, 183 



correct description jet when thej are calcined there is found 

 to be an organic circle at the base ; the spines nevertheless 

 hold together, showing that this surrounds calcareous matter. 



The rosette-plates are small and numerous, forming a line 

 along the middle of the wall. 



Loc. Living : Victoria ^ Kerguel en Island ; S.Patagonia; 

 New Zealand; Holborn Island ; Vaucluse Point, Port Jackson, 

 5 fath. Fossil: Aldinga; Australia; and Napier, New Zea- 

 land. 



29. Memhranijaora roborata^ Hincks. 



Memh-anipora roborata, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. 

 viii. p. 69, pi. ii. fig. 3 ; Waters, Quart. Journ. Geol. Soc. vol. xxxix. 

 p. 483. 



Flustra membraniporides, Busk, Cliallenger Report, p. 54, pi. xxxii. 

 fig. 7 (unilaminate). 



Craspedozoum Ugulatiim, MacGillivray, Descriptions of New or Little- 

 known Polyzoa, pt. ix. p. 5, pi. i. fig. 3. 



Craspedozoum spicatum^ MacG. ibid. p. 5, pL i. fig. 2. 



Bilaminate specimens from Port Jackson have usually two 

 avicularia, but sometimes only one, and the spines are small 

 and not always found, but there are two on the outer corner of 

 the outside zooecia. This is broader than the unilaminate form 

 from New Zealand, which has usually only one avicularium 

 to a zooecium. The ovicells in both are similar in character, 

 though those from New Zealand have a rounded border. 

 Busk does not mention the tubular tibres at the side of the 

 zoarium. As I have pointed out, in the unilaminate form 

 from New Zealand there are at the commencement of a new 

 branch frequently chitinous tubes from cell to cell, so that 

 they may be considered articulated. In the bilaminate speci- 

 mens from Port Jackson there are sometimes chitinous tubes 

 on the front passing from one zooecium to another, sometimes 

 to the next, at other times passing over several, and near the 

 place where fresh branches are given off lateral tubes often 

 start from central zooecia. 



Loc. Curtis Island ; Port Jackson, 8 fath. (bilaminate) 

 [Braz.) ; New Zealand ; Port Phillip Heads ; Bass's Strait. 

 Fossil : Waurn Ponds (unilaminate) . 



30. Membranipora FlemingUy var. mtnax, B. 



Membranipora minax, Busk, Quart. Journ, Microsc. Science, vol. viii. 

 p. 125, pi. XXV. fig. 1 ; Hincks, Brit. Mar. Polyzoa, p. 169, pi. xxii. 



Membranipora Flemingii, forma mi7iax, Sniitt, Krit. Fort. o. Skand, 

 Hafs-Bryozoer, CEfv. K. Vetensk.-Ak. Forh. 1867, pp. 368, 409, pi. xx. 

 fig. 43. 



A specimen from the Sow-and-Pigs Reef, Port Jackson, 



