General History of the Marine Polyzoa. 289 



on a zooecial area of reduced size, in a line with the cells, and 

 very clearly betrays its relationship to the ordinary orifice. 

 But in the present case the structure has attained a very con- 

 siderable degree of specialization ; it is erect and free, attached 

 by its base to the zoarium and bearing the mandible at the 

 opposite pole. Flustra nobilis is clearly a species which has 

 departed to some extent from the ordinary Flustrine type. 



Family Membraniporidae. 

 Membranipoea, De Blainville. 



Membranipora eburnea, sp. n. (PI. VII. fig. 5.) 



Zoarium incrusting. Zooscia quincuncial, crowded, porcel- 

 laneous, with a white and glossy surface, pyriform, much 

 produced below, the lower half of the area (which occupies 

 the whole front and has a membranous covering) roofed in by 

 an extension of the cell- wall, which slopes rather steeply 

 upwards and is continuous above with the elevated margin 

 surrounding the upper portion of the area, the margin fur- 

 nished with stout, pointed, calcareous processes, which bend 

 slightly inward ; two or three are also commonly present on 

 the wall which closes the cell below ; orifice small, semi- 

 circular, placed at the very top of the area. Ooeciumi?). 



Loc. ? Queensland [Miss Jelly). 



Family Myriozoidse (part), Smitt. 



Schizopoeella, Hincks. 



Schizoporella concinna, sp. n. (PI. VI. figs. 2.) 



Zoarium erect, cup-shaped. Zooecia on one surface only, 

 quincuncial, of large size, subquadrangular or ovate, somewhat 

 depressed, separated by thin raised lines, the sutures shallow, 

 surface silvery, thickly covered with round perforations ; orifice 

 ample, much broader than high, arched above, the sides 

 straightish, very slightly constricted below by the articular 

 processes, lower margin straight, thin, with a rather shallow 

 central sinus, rounded below, the opening, when perfect, con- 

 tracted by a small denticular projection on each side ; peri- 

 stome slightly raised, operculum membranaceous ; a ridge-like 

 elevation of the zooecial wall inclosing the orifice below ; on 

 each side of the latter, a little below the top, a small, slightly 

 raised avicularium with rounded mandible (PI. VI. fig. 2 a) ; 

 occasionally a minute avicularium close to the sinus, placed 

 transversely. Oozcium ('?). 



