86 BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 



rounded by a thin and salient peristome; the proximal lip is very convex and bears 

 two very small lateral denticles. The orifice of the ovicell, which is endotoichal, 

 is small. The zooecia bearing branches are narrow, with an elliptical elongate orifice. 

 The interzooecial avicularium is elliptical or subrectangular; its opesium is irreg- 

 ular. 



,, , A ^ (/(ff = 0.15mm. „ . fi2 = 0.85mm. 



Measurements. — Apertura 7„_n i" mm Ziooecia , _ „_ 



^ [la — UAi mm. [ te = 0.30 mm. 



Affinities. — In the determination of Cellaria, one must take into considera- 

 tion the zooecia bearing branches which are somewhat equivalent to the "basis 

 ramae" of Crisia. Their orifice serves as a place for a horny cylindrical joint. 



This species differs from Cellaria mandihvlata Hincks, figured by Miss Robert- 

 son, 1905, in the small round orifice of the ovicell and in the form and size of its 

 zooecia bearing branches, which are narrow and provided with an elongate orifice 

 and not transverse, and in the absence of large avicularian zooecia. 



Occurrence. — Pleistocene: Santa Monica, California (rare). 



Coty pes. —C&i. No. 68516, U.S.N.M. 



CELLARIA MANDIBDLATA Hincks, 1882. 



Plate 34, figs. 11-14. 



1882. Cellaria mandibtdata Hincks, Polyzoa of the Queen Charlotte Islands, Annals and Maga- 

 zine Natural History, ser. 5, vol. 10, p. 462; 1884, ser. 5, vol. 13, p. 203, p, 9, fig. 7. 



1905. Cellaria manflibulata Robertson, Nonincrusting Cheilostomatous Bryozoa of the West 

 Coast of North America, University of California Pulilications, Zoology, vol. 4, no. 5, 

 p. 288, pi. 15, figs. 87, 89; pi. 16, fig. 103. 



,, J A 4. (?i-a = 0.07mm „ . fiz = 0.60min 



Measurements. — Apertura , „ , , Zooecia , „ „„ 



^ |to = 0.14mm. lZ2 = 0.39mm. 



Variations. — The orifice of the ovicell is quite variable; sometimes it is an 

 ellipse, elongate and narrow: more often it is an orbicular orifice. The two forms 

 may exist on the same segment. The avicularian zooecia are enormous and com- 

 parable to those which are observed on the recent specimens. The reader will 

 comprehend their function by studying Miss Robertson's figure 88. The orifice 

 of the zooecia bearing branches is round, surrounded by a salient peristome. 



Occurrence. — Pleistocene : Los Angeles, California (very common) . 



Habitat. — Pacific Ocean off San Pedro and San Diego, California. 



Plesiotypes.— Cat. No. 68517, U.S.N.M. 



CELLARIA DIFFUSA Robertson, 1905. 



Plate 34, figs. 19, 20. 

 1905. Cellaria diffusa Robertson, Nonincrusting Cheilostomatous Bryozoa of the West Coast of 

 North America, University of California Publications, Zoology, vol. 4, no. 5, p. 289, 

 pi. 15, fig. 90; pi. 16, fig. 104. 



We have found very few fragments of this large and superb species. We 

 have observed the same proximal tongue in the orifice of the ovicell, the same 

 proximal convexity of the apertura, and the same rectangular interzooecial avicu- 

 larium. Our micrometric measurements would be slightly larger if the scale of 

 Miss Robertson be exact. 



Occwrrewce.— Pleistocene : Santa Monica (Rustic Canyon) and Los Angeles, 

 California (rare). 



Habitat. — Pacific Ocean off California. 

 Plesiotype.—C&t. No. 68518, U.S.N.M. 



