VoL, 2] Robertson.—Non-Incrusting Bryozoa. 267 
more mm. in diameter (Pl. XVI, fig. 98), or of much elon- 
gated, narrow, strap-like branches (fig. 99). Zoawcia multi- 
serial, the branches having from three or four, to twelve or four- 
teen rows; alternate, oblong, slightly narrower below, truncate 
above (Pl. X, fig. 48); aperture occupying more than half the 
front; an erect spine at each upper outer angle (sp.); a varying 
number of marginal spines, two to five on the inner margin, one 
to three on the outer, curving inward; occasionally in the ab- 
sence of an avicularium, a spine at the bottom of the aperture, 
curving upward (ba. sp.). Avicularia pedunculate, those on 
the marginal zowcia, when present, much larger than those on 
the intermediate zoccia; often absent from both marginal and 
intermediate zocecia. Oacia (oe.) large, subglobose, marked by 
radiating lines. Rootlets given off from marginal zocecia near 
base of colony. 
B. murrayana is found at Kadiak, Orea, Pribilof Islands, 
Alaska, and in Puget Sound, but does not extend farther south. 
The specimens from Orea, Prince Williams Sound, are ro- 
bust, often possessing a large number of zocecia in a series form- 
ing broad strap-like segments or branches (Pl. XVI, fig. 98). 
Those from Kadiak and Puget Sound are more delicate in ap- 
pearance, forming smaller colonies (fig. 99). Those dredged at 
ten fathoms in Puget Sound do not possess more than six or eight 
rows of zocecia in a series. There is great range of variation in 
the number of spines, and in the number and size of avicularia, 
among the specimens from the different localities. A consid- 
erable quantity of material from Pribilof Islands possesses the 
large marginal avicularia, while most of the material from other 
localities lacks them. 
17. Bugula californica sp. nov. 
Pl. X, fig. 49; Pl. XVI, fig. 100. 
Zoarium consisting of a number of masses whose branches 
have a distinetly spiral arrangement about a central axis, some- 
times forming a coarse growth 75 mm. in height and from 25 
to 50 mm. in diameter in the broadest place (Pl. XVI, fig. 100). 
