Vou. 2] Robertson.—Non-Incrusting Bryozoa. 281 
the bifureation (fig. 74, b7.), 7.e., the branches bifureate between 
two series of zocecia forming the proximal branch and not upon 
a single zoecium. Zowcia (z@.) of the Bugulan type, elongated, 
turned outward, but aperture not turned distinctly upward; 
aperture elongated, occupying more than half the front surface, 
the lateral margins raised and terminating at the upper angles 
in long curving spines (c. sp.). Two or three spines (sp.) on 
the upper, outer margin, and one on the inner (sp.). Avicularia 
(av.) peduneculate, situated below and to one side of the aper- 
ture; present usually on every zoccium. Oacia (oe.) peduncu- 
late, to one side of the summit of the zocecium. Rootlets arising 
from the lower segments of the stalk, proceeding downward 
close to it, and at its base spreading freely and attaching them- 
selves to the substratum, becoming entangled with those of other 
colonies and forming a sort of cable whose strands are further 
bound together by organisms parasitic upon them. 
These two species S. ciliata and S. occidentalis resemble each | 
other in habit of growth, but the zocecial portion of the latter 
is relatively shorter and the stalks relatively longer than are 
those of 8. ciliata. This is so evident that a macroscopic exam- 
ination is sufficient to separate them. The greater length of the 
stalks of S. occidentalis is due probably to the greater length of 
many of the segments and not to a greater number of segments. 
Thus a segment of the lower part of a stalk shown in Pl. XIV, 
fig. 76, is twice the length and thickness of those of the upper 
portion of the same stalk represented in Pl. XIII, fig. 73. 
This species is found in several localities on the coast of Cali- 
fornia and Puget Sound. 
28. Stirparia californica sp. nov. 
Pl. XIII, fig. 75; Pl. XIV, figs. 77, 78, 79, 80. 
Zoarium consisting of tall stalks surmounted by large, feath- 
ery, branching tufts of zocecia (Pl. XIII, fig. 75); the stalk, 
both absolutely and relatively, longer in this species than in 
the two preceding, being two and a half or three times as long 
as the zowcial tufts. Segments of the stalk stout, some very long, 
