General History of the Marine Polyzoa. 367 
cylindrical form of Flustrella hispida just described, and must 
rank in the same genus. 
The cells in the same longitudinal series are not in imme- 
diate contact, but are connected one with the other by a 
peduncular extension, which is bounded like the cell itself by 
a dark reddish-brown line. Nor are the cells in neighbouring 
rows united laterally, a narrow interspace lying between the 
series and extending throughout the length of the branch. 
In the isolation of the cells this species differs from FP. his- 
pida. ‘There is no true joint at the origin of the branches, 
but merely a constriction, and the zocecia run on continuously. 
This form and the preceding illustrate a very different 
phase of the genus Llustrel/a trom that to which we have 
been accustomed, and show that it has a wide geographical 
range. 
Suborder CHEILOSTOMATA. 
Family Cellulariide. 
Buauta, Oken. 
Bugula uniserialis, n. sp. (Pl. XIII. fig. 8.) 
Zourium minute, composed of geniculate, slightly branched 
shoots of transparent texture and a delicate horn-colour ; 
branches given off sparingly from about the middle of the 
dorsal surtace of a cell. Zoawcia uniserial; bent alternately to 
opposite sides, so as to present a zigzagged appearance, each 
cell originating on the dorsal surtace of the one beneath it, 
immediately below the top and directed obliquely outwards, 
boat-shaped, of equal width in the upper portion, slightly 
contracted below ; aperture occupying the whole front, and 
closed by a transparent membrane ; margin thin, running out 
above at each side into a sharp spinous projection; at the top 
of each cell a very minute articulated avicularium, placed 
just below the upper margin and usually about the middle of 
it, well rounded behind, with a rather long back sloping 
down to a well-developed beak, mounted on a rather promi- 
nent peduncle. Oaciwm helmet-shaped, smooth and shining, 
placed on the side of the cell close to the top, and overhanging 
the orifice more or less. 
Loc. Western Australia, on weed (Miss E. Gore). 
This species is probably the minutest of its tribe (so far 
as known), and is very scantily branched and simple in habit. 
Though the uniserial and geniculate character of the cells 
