270 University of California Publications. | ZooLocy 
the same zocecium, and probably on account of the purely me- 
chanical obstruction caused by the embryo. 
The distribution of B. pacifica extends from Pribilof Islands, 
Bering Sea, to San Francisco Bay. It has been obtained from 
St. Paul, Pribilof Islands; is very abundant at Yakutat, and is 
found in smaller quantity at Orea, Prince William Sound, 
Alaska; abundant, but colonies smaller, at Sidney, opposite 
Port Orchard Navy Yard, Puget Sound, less abundant on Chan- 
nel Rocks, Puget Sound; fine colonies obtained from rocks at 
Dillons Beach, California; smaller quantity obtained from Lime 
Point and Fort Point, San Francisco Bay, California. 
19. Bugula flabellata J. V. Thompson. 
Pl) axe dies SoZ: 
Bird’s Head Coralline Ellis, 1767, Ger. ed., p. 109, Pl. XXXVIII, 
Olt. 
Cellularia avicularia (part) Pallas, 1766, p. 68. 
Flustra avicularis, Johnston, 1847, p. 346, Pl. LXIII, figs. 3, 4. 
Avicularia flabellata Thompson, 1847, MS. Brit. Mus.; Gray, Brit. 
Mus. Radiata, p. 106. 
Avicella avicularia Van Beneden, 1848, p. 75. 
Ornithoporina avicularia, d’Orbigny, 1850, p. 322. 
Bugula flabellata, Busk, 1852, p. 44, Pls. LI, LILI. 
Bugula avicularia forma 2, B. flabellata, Smitt, 1867, pp. 290, 345. 
Bugula flabellata Thompson, 1868, Pl. VI, fig. 9. 
Bugula flabellata, Norman, 1868, Pl. VI, fig. 9. 
Bugula flabellata, Smitt, 1871-72, pt. I, p. 18, Pl. V, figs. 48-52. 
Bugula flustroides, Verrill, 1879, p. 52. 
Bugula flabellata, Hincks, 1880, p. 80, Pl. XI, figs. 1-3. 
not Bugula flabellata, Robertson, 1900, p. 431. 
Zoarium from 12-25 mm. in height, consisting of a number 
of fan-shaped fronds divided into narrow branches (fig. 51). 
Branching dichotomous, occurring where a branch reaches a 
width of six or seven rows of zoccia. Zowcia elongated, of about 
equal length throughout, aperture occupying the whole or almost 
the whole of the front; usually two spines placed one above the 
other at each upper angle, the upper spines stiff and flaring, 
the lower often of great length and frequently crossed in front; 
on marginal zocecia there are generally three spines on the outer 
side and two on the inner (fig. 52). Avicularia less than half 
