198 
BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 
TUBULIPORA TUBA Gabb and Horn, 1862. 
Plate 42, figs. 18-23. 
1862. Semitubigera tuba Gabb and Horn, Monograph Polyzoa of the Secondary and Tertiary forma¬ 
tions of North America, Journal Academy Natural Sciences Philadelphia, ser. 2, vol. 5, 
p. 169, pi. 21, fig. 57. 
1910. Tubulipora occidentalis Robertson, Cyclostomatous Bryozoa of the west coast of North Amer¬ 
ica, University of California Publications, Zoology, vol. 6, p. 249, pi. 22, figs. 29-31. 
Measurements. —Diameter of the peristome, 0.12 mm. 
Variations. —The zoarium creeps on algae, with generally flabelliform fronds; it 
sometimes entirely surrounds the delicate radicells and thus becomes tubular. We 
have observed some specimens on other bryozoa. 
The fascicles are monoserial or biserial; they have a large number of tubes, 
from 6 to 20; they are often arranged on each side of the zoarial axis in rather 
irregular order. 
The ovicell is large and is inserted between six or eight fascicles. The oecios- 
tome is a very small tube, quite salient, adjacent to the first tube of a fascicle. 
Affinities. —This species differs from Tubulipora fasciculifera, Hincks, 1884, in 
its long fascicles composed of more than six tubes and in its long capillary oecios- 
tome. 
Occurrence. —Pleistocene: Santa Monica (Rustic Canyon), (rare), Dead Mans’ 
Island, off San Pedro (rare), and Santa Barbara (rare), California. 
Habitat. —Pacific: Off California, and the Queen Charlotte Islands. 
Plesiotype. —Cat. Nos. 68738, 68739, U.S.N.M. 
Genus IDMONEA Lamouroux, 1821. 
(For description, see Bulletin 106, U. S. National Museum, p. 770.) 
IDMONEA DISPAR, new species. 
Plate 41, figs. 6-10. 
Description. —The zoarium is free, bifurcated, with subcylindrical section; the 
branches are undulated and at a bifurcation; they are not equal. The fascicles 
are alternate or almost opposite and diverge from each side of the median crest. 
The tubes are visible, convex, and three or four in number to a fascicle; the 
peristome is thin and orbicular. 
Measurements. —Width of salient fascicles_0.14 mm. 
Width of little salient fascicles__._0.20 mm. 
Diameter of first zooecium (on the zoarium).0.18 mm. 
Distance between the fascicles..... 0.40-0.60 mm. 
Zoarial diameter..... 0.80 mm. 
Affinities. —This species is quite well characterized by the inequality of the 
branches at the bifurcations; there is always one a little smaller than the other. 
Occurrence. —Pleistocene: Santa Monica (Tremochal Canyon) ,California (com¬ 
mon). 
Cotypes. —Cat. No. 68740, U.S.N.M. 
