358 Rey. T. Hincks’s Contributions towards a 
Membranipora marginella, n. sp. (Pl. XIII. fig. 1.) 
Zowcta rather small, quincuncially arranged, ovate or pyri- 
form, sometimes pointed below, with a rather thick, unarmed, 
minutely granular margin; aperture occupying about two 
thirds of the front and closed in by membrane, contracted above 
and expanded and rounded below ; a small oval avicularium, 
elevated above and sloping downwards, borne on the margin of 
the zocecia, usually placed on the side, near the top. Occa- 
sionally cells with a very large oral operculum of a dark horn- 
colour, occupying nearly half the area, and enclosed by a 
thin raised border (? avicularian or reproductive). 
Family Steganoporellide. 
STEGANOPORELLA, Smitt. 
Steganoporella magnilabris, Busk. 
Range. Abrolhos Islet (south tropical Atlantic), Algoa 
Bay, Bass’s Straits, Florida. 
Smitt places this genus amongst the Microporide, and I 
have given it the same position in my ‘ History of the 
British Marine Polyzoa.’ But I am now imclined to agree 
with Dr. J. Jullien * so far as to regard the dithalamic con- 
dition of the zocecium which distinguishes it as entitling it to 
rank in a separate family group. It is only right, however, 
that the name of this group should be taken from Smitt’s 
genus Steganoporella, which is founded on the division of the 
zocecium into an upper and lower chamber by the interposition 
of a calcareous lamina beneath the membranous front wall. 
I am unable to follow Dr. Jullien in his proposed distribu- 
tion of the Cheilostomata into two principal groups, charac- 
terized by the presence or absence of this ‘‘ double ectocyst.” 
It seems to me that he assigns a significance to this struc- 
tural peculiarity to which it is by no means entitled. There 
is room, however, for a fuller investigation of its history and 
meaning. 
SMITTIPORA, J. Jullien. 
Smittipora abyssicola, Smitt. 
Range. Cuba, Florida, Singapore or Philippines. 
es 
* See his interesting paper entitled “ Note sur une nouvelle division 
des Bryozoaires Cheilostomiens,” Bull. de la Soc. Zool. de France, t. vi. 
(1881). 
