General History of the Marine Poly zoa. 117 



rous denticles along the inner edges ; margins thin, smooth, 

 very little raised. Ooecia immersed, of large size, tall, of 

 delicate material, perfectly smooth and shining. Avicularia 

 none. 



Log. West Australia {Miss Jelly). 



In some respects allied to F. denticulata, Busk, and notably 

 in being furnished with marginal denticles, but differing from 

 it in many points. It is quite destitute of spines and avicu- 

 laria ; and the ooecium is immersed, whereas in F. denticulata 

 it is external and bears the large avicularium on its front. 

 In the mode of branching and general appearance the two 

 species are also very dissimilar. 



I have only seen small pieces of F. dentiyei-a, and can 

 therefore give no account of the size which it attains ; its 

 habit of growth is very distinctive. 



This form is not described in any of the Australian jmpers 

 which I have met with, and seems to be new. 



Family Membraniporidae. 



Membeanipora, De Blainville. 



Memhranipora pilosa, Linna3us, form multispinata, 

 (PI. V. %. 6.) 



Zocecia claviform, ovate above, narrowing off gradually 

 towards the base ; area occupying about two thirds of the 

 front, with a membranous covering ; margin thin, smooth, 

 bearing on each side eight to ten slender compressed spines 

 set very closely together, which bend abruptly inward, meeting 

 and intcrdigitating in the centre ; a single erect, rather stout, 

 acuminate spine on each side at the top ; immediately below 

 the area a similar spine rising from a socket on the front 

 wall ; portion of the cell below the area smooth and silvery, 

 bearing near the bottom two large membranaceous spines, placed 

 one on each side, which sometimes attain a great length. 

 No avicularia. Ooecia. (?). Zoarium expanding regularly 

 from the point of origin to a width of about four cells, and 

 bifurcating at intervals ; sometimes forming a regular crust. 



Loc. "West Australia, on weed [Miss Jelly). 



M. 2nlosa is liable to so much variation that I do not ven- 

 ture to separate the present form from it, though it has a very 

 definite character of its own. 



Its chief peculiarities are the great number of the marginal 

 spines, which are compressed and set closely together, and 

 very much bent in, so as to present the appearance of a ribbed 

 covering to the area, and the absence of the disks which 



