Mr. A. W. Waters on Australian Bryozoa. 189 



mud bottom. Fossil : European Pliocene ; Australia ; New 

 Zealand. 



43. Microporella tetrastoma^ Rss., var. 



Type Bschara tetrastoma, Rss. Sitz. Ak. Wien, 1864, vol. 1. p. 9, pi. ii. 

 fig. 9. 



There is a small fragment of a Microporella from Darnley 

 Island, of which the zoarium has consisted of thin flattened 

 foliaceous branches. The pyriform zooecia have two or 

 sometimes three pores below the oral aperture, and below 

 these a raised boss or umbo. 



It does not seem advisable to name so small a fragment, 

 since this group shows great variation in the zooecia. I have 

 recent M. tetrastoma from Port Phillip, with a broad foliace- 

 ous growth, in which the outer cells have merely an elon- 

 gate denticulated pore, whereas the central ones have numerous 

 denticulated pores ; on each side of the suboral pore there is 

 a small avicularium directed diagonally upwards ; usually the 

 aperture, pore, and avicularia are placed in a deep pit, but 

 this is not always the case, and the central zooecia are usually 

 larger and more raised. 



Microporella tetrastoma is no doubt the M. clavata from 

 Curdles Creek (Quart. Journ. Geol. Soc. vol. sxxvii. p. 3ii2), 

 and the Adeonellopsis parvipuncta^ MacGr. 



Loc. Darnley Island, Torres Straits, 10-30 fath. 



44. Porina larvalis, MacG. (PI. VI. fig. 8.) 



Lepralia larvalis, MacGillivray, Nat. Hist, of Vict. dec. iv. p. 30, pi. 



xxxvii. fig. 5. 

 Porhia larvalis, Waters, Quart. Journ. Geol. Soc. vol. xxxviii. p. 289, 



pi. viii. fig. 195 MacGillivra}^, Cat. Mar. Polyzoa of Victoria, p. 27, 



As I have already pointed out, the question of the generic 

 position is a difiicult one ; but as the two large pores open into 

 the throat of the peristome and not below the oral aperture, I 

 placed it with Porina, and in this it seems that Mr. MacGil- 

 livray agrees. 



The mandible is simple with a plain lower edge without 

 articular processes, but there are two characteristic diagonal 

 muscular ridges immediately below the lucida. 



Loc. Fossil : (with cylindrical zoarium) Bairnsdale. Re- 

 cent : Victoria ; West Australia ; Bondi Bay, N. S. W. 



45. Porina coronata, Rss. (PI. VI. fig. 5.) 



For synonyms see Waters, Quart. Journ. Geol. Soc. vol. xli. p. 297. 



This was described as coronata by Reuss, and as gracilis 

 by Lamouroux and others, but most of the descriptions were 



