General History of the Marine Polyzoa. 297 



cell-wall and projecting considerably, supporting an avicu- 

 larium with a narrow lanceolate mandible, the beak slightly 

 hooked at the extremity; on one side of the umbo a pointed 

 and raised avicularium, directed obliquely downwards, some- 

 times a large number of such avicularia irregularly distri- 

 buted. Ooscium large, prominent, subglobose, well rounded 

 above, narrowing towards the orifice, frequently a penthouse- 

 like projection above the oral arch, surface punctured, a 

 profusion of avicularia of various sizes on and around the 

 ocecium. 



Hob. Incrusting a Gellepora and spreading over Flustra 

 armata, Busk. 



Loc. Port Elizabeth, South Africa {Miss Jelly). 



This species is assigned somewhat doubtfully to Lepralia. 

 The structure of the orifice does not conform very markedly to 

 that which is characteristic of this genus ; but, on the whole, 

 it is perhaps more nearly allied to it than to any other group. 



The front wall of the zocecia may be described as reticulate, 

 so completely is it occupied by large perforations, with a 

 narrow line separating them. The avicularia are present in 

 great numbers and are all of the same type and furnished with 

 lanceolate mandibles. In some parts of the colony, and 

 especially in the neighbourhood of the ocecia, they literally 

 swarm. Under these circumstances there is no regularity of 

 arrangement ; they are of all sizes and turned in all direc- 

 tions. In the older zocecia the surface is sometimes much 

 roughened, and large areolse extend from the margin towards 

 the centre. The true character of the cells is best studied in 

 the younger portions of the colony, in which the suboral 

 avicularium and perhaps one or two others form the whole 

 contingent. 



Muckonella, Hincks. 



Mucronella aviculifera, sp. n. (PI. VII. fig. 2.) 



Zoarium incrusting. Zooecia of large size, quincuncially 

 disposed, broad-ovate, convex, separated by rather deep 

 sutures, strongly calcified, the front wall thickly covered over 

 its whole extent with round perforations, surface silvery 

 white ; orifice orbicular, the peristome slightly raised and 

 forming a thick collar round it, a central bifid denticle within 

 the lower margin and a small pointed denticle on each side, 

 operculum membranaceous, finely furrowed from the top to 

 the hinge-line, which crosses it just above the denticles ; on 

 the raised collar-like margin (immediately in front of the 



