Vor. 2] Robertson.—Non-Incrusting Bryozoa. 289 
corner, and two others opposite at the corners of the upper mar- 
gin. Avicularia (av.) characteristic, large, few in number, only 
one or two in an internode, of simple form, almost exactly lke 
extra large zocecia; much broader than ordinary zocecia, with a 
large semicircular chitinous mandible extending upward, whose 
upper margin is considerably elevated above the surface of the 
internode; above the avicularium is a small orifice resembling 
in shape and position an immature occium (or.) Oa@cia not 
found in the youngest zocecial stage described above. In older 
stages the orifice of the ocecium (fig. 88, oe.) appears circular, 
or somewhat oblong, occupying the space on each zocecium above 
the operculum; in the fully developed stage (fig. 89, oe.), the 
ocecia resemble minute avicularia, with a straight lower margin, 
semicircular above and slightly raised above the surface of the 
zocecium. Numerous fine brown rootlets spring from the lower 
zocecia of the colony. 
Without doubt this is the species described by Hinecks from 
Queen Charlotte Islands. It is readily distinguished from other 
Cellaria of this region by its large dark avicularia which may 
be seen easily with a lens of low power. The method of branch- 
ing, which Hincks seems to think is probably not characteristic 
of the species, is certainly typical both of this and another spe- 
cies, C. diffusa, less commonly found here. C. mandibulata has 
a wide distribution but is most common in southern waters, 
being frequently dredged in the vicinity of both San Pedro and 
San Diego. 
33. Cellaria diffusa sp. nov. 
Pl. XV, fig. 90; Pl. XVI, fig. 104. 
Zoarium consisting of a relatively small number of rather 
long cylindrical internodes connected by dark chitinous joints; 
imternodes varying in length, the longest attaining a leneth of 
39 or 40 mm., the whole colony often 75 mm. high, and having 
a strageling diffuse appearance due to its method of branching. 
Branching irregular, branches arising at any point on an inter- 
node, always in the middle of a zoccium; two branches, some- 
times three or four arising at the distal end of the internode 
