ABT. 14 FOSSIL AND KECENT BRYOZOA CANU AND BASSLER 19 



1922. Membranipora iuherculata Makcus, Siidafrikanische Bryozoen aus der 



Sammlung des Gothenburger Museum. Ktingl Vetenskaps och 

 Vitterhets Samhalles Handlingar, vol. 25, p. 15, fig. 8. 



1923. Membranipora tuberculata Canu and Bassler, North American Later 



Tertiary and Quaternary Bryozoa. Bull. 125, U. S. National Mu- 

 seum, p. 22, pi. 33, figs. 3-5. (Bibliography and distribution.) 



Marcus has erroneously placed in the synonymy of this species 

 Biflustra denticulata Smitt, 1872, which is quite a different species 

 belonging to the genus Hemiseptella. 



The present species is very fragile and in drying, the zooecia 

 become greatly deformed. The development of tubercles is very 

 irregular even on the same specimen, as is apparent in one of our 

 figures of 1923. 



Biology. — It was believed formerly that this species was confined 

 to the American Continent but the discoveries of Marcus showed 

 that it had traveled around Africa and had extended into the Indian 

 Ocean, where Miss Robertson noted it, and also into the western 

 Pacific, where we have observed it in the PhiHppines. This is then a 

 universal species, quite cosmopolitan, transported on algae by the 

 great marine currents. In the Northern Hemisphere it does not pass 

 beyond the fiftieth parallel. 



Occurrence. — Albatross Station D. 2647. Straits of Florida, 25° 

 48' 00" N.; 80° 04' 00" W.; 85 fms.; gray sand, 

 foraminifera. 

 Atlantic: Straits of Florida; Tortugas (Osburn) ; Ber- 

 muda (Verrill). 



Geographic distribution. — Pleistocene of California. South Africa 

 (Marcus); Philippines. 



Cat. No. 7549, U.S.N.M. 



Family FLUSTRIDAE Smitt, 1867 



Genus FLUSTRA Linnaeus, 1761 



FLUSTRA (CARBASEA) CAPITATA, new species 



Plate 28, Figures 4, 5 



Description. — The zoarium is free, unilamellar, formed of narrow 

 fronds with five longitudinal series of zooecia. The zooecia are 

 distinct,; separated by a common salient thread, elongated, somewhat 

 lozenge-shaped. The mural rim is thin and the opesium entire. 

 The opercular valve is adjacent to the mural rim and its border is 

 much chitinized. The ovicell is very large, endozooecial, very convex; 

 the ectooecium is incompletely calcified and leaves a circular area on 

 which an avicularium is sometimes placed. The avicularium is distal, 

 obhque, always adjacent to the mural rim; the beak is oriented 

 toward the aperture; the mandible is semicircular. 



