a General History of the Marine Polyzoa, 129 
the margin, composed of tubular fibres laid closely to- 
gether, which at the base form a considerable tuft of root- 
lets. Zoewcia quincuncially arranged, ovate, often running 
out to a poimt below; margin thin, smooth, two short and 
rather stout spines above; aperture ovate, occupying the 
whole front, with a membranous covering, depressed, the 
cell-wall surrounding it minutely granular, expanded below ; 
above each cell two raised and pointed avicularia placed side 
by side, the mandible directed downwards. Ocaciwmmitriform, 
flattened and smooth in front, surrounded by a thickened border, 
which rises into a blunt point in the centre. 
Loc. Off Curtis Island, abundant in the dredgings. 
The tubules which constitute the rib along the edge of the 
zoarium (as in Lschara flabellaris, Busk) are given off from 
the side of the marginal zocecia ; they strengthen, and support, 
and hold together the rigid but slender stem and branches, 
and secure a certain amount of flexibility to the whole struc- 
ture; at the base they run out into a multitude of (quas¢) 
root-fibres. 
Note on Catenicella. 
In Capt. Warren’s collection there is a fair representation 
of the characteristic Australian group of the Catenicellide ; and 
amongst the forms occurring there are two or three which 
I cannot identify with any described species; but as I have 
not been able as yet to obtain all the papers dealing with this 
tribe they must be reserved for future examination. 
VIL FOREIGN MEMBRANIPORINA (third series). 
MEMBRANIPORA, De Blainville. 
Membranipora amplectens, n. sp. 
(Pl. III. fig. 7.) 
Zoecia pyriform, disposed in single series, which bifureate 
at intervals; surface smooth, frequently a line of minute pores 
on each side, extending from the aperture to the bottom of the 
cell ; aperture oval, occupying more than half the front, with 
a membranous covering ; margin smocth, slightly thickened, 
two spines at the top, two on each side, and a tall vibraculoid 
spine, calcareous, with a corneous joint at the base, imme- 
diately below the aperture. No avicularia. Oacium borne on 
a special cell, which is always situated in the fork between two 
branches, elongate, rounded at the top, composed of a number 
of flattened pieces or ribs placed close together, which spring 
from the opposite sides and unite in the centre, a line (mark- 
