Rev. T. Hlncks or, British Polyzoa. 213 



Suborder Cheilostomata, Busk. 



Genus Membranipora, De Blainville. 

 1. Membranipora nodulosa^ n. sp. 



Zoooecia small, oval, margin slightly raised, granular, un- 

 armed ; more than half the area covered in by a minutely 

 granulated calcareous lamina ; orifice occupying rather more 

 than a third of the area, arched and somewhat contracted above, 

 lower margin straight, obscurely trifoliate ; at the base of each 

 cell a very large, prominent, smooth nodule, usually subtri- 

 angular in shape : oooecia very small and shallow, rounded, 

 smooth. 



Colonies forming small and very inconspicuous crusts. 



Localities. Coast of Antrim [Hyndman) ; South Devon, off 

 Brixham {T. H.). 



Distinguished from M. Bosselii, to which it is allied, by the 

 much smaller size and oval form of the cell, the continuous 

 and very slightly granular margin, and the large and conspi- 

 cuous intercellular bosses or nodules. 



2. Membranipora aurita, n. sp. 



Zoooicia ovate, somewhat expanded below, disposed with 

 great regularity in quincunx ; area with a membranous cover- 

 ing, no calcareous lamina ; margin plain, on one side, about 

 halfway down, a blunt, short spine ; immediately above each 

 cell, or the ovicell, when present, two raised avicularia, one on 

 each side, with a pointed mandible, usually directed upwards 

 and slightly outwards : oooecia subglobose, partially immersed, 

 with a strong rib on the front, rising to a point above and 

 inclosing a triangular space. 



Colonies forming large, subcircular patches, resembling the 

 most regular lacework. 



Localities. Antrim {Hyndman) ; Cornwall and South Devon 

 {T. //.) ; Northumberland {Alder). 



Distinguished from M. Flemingii by the more regularly 

 ovate form of the cell, the entire absence of a calcareous 

 lamina, the triangular figure on the front of the ovicell, and 

 the perfectly regular quincuncial arrangement of the cells. 



3. Membranipora JlustroideSy n. sp. 



Zoooecia large, in regular lines, set closely together, oval ; 

 margin witli 12-14 massive, flattish, sometimes subclavate, 

 sometimes bitid spines, which bend inwards and meet across 



