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PEOCEEDIN-GS OP THE l^ATIOISTAL MUSEUM 



VOL. 72 



''The color is a deep blue black or violet" (Osburn). The margin 

 of the aperture is usually of a little whitish tint in contrast with the 

 black-bluish color of the zooecial wall (Smitt) . 



Occurrence.— Albatross Station D. 2320, north of Cuba; 23° 01' 39" 

 N.; 82° 18' 48" W.; 130 fms.; fine coral. 

 Tortugas, 9 meters (Osburn) ; Florida, 21 meters 

 (Smitt) . 

 Plesiotype.—C&t. No. 7522, U.S.N.M. 



Genus HOLOPORELLA Waters, 1909 



HOLOPORELLA ALBIROSTRIS Smitt, 1873 



Plate 22, Figures 10, 11; text Figure 31 



1889. Cellepora albirostris Jelly, A Synonymic Catalogue of Marine 



Bryozoa, p. 45. 

 1914. Holoporella albirostris Osburn, Bryozoa of the Tortugas Islands. 



Publication Carnegie Institution, Washington, No, 182, p. 215. 

 1923. Holoporella albirostris Canu and Bassler, North American Later 



Tertiary and Quaternary Bryozoa. Bull. 125, United States 



National Museum, p. 174, pi. 7, figs. 9-14, pi. 32, figs. 6-10. 



Measurements. — Diameter of the apertura, 0.14 mm. 

 Structure. — We have little to add to the natural history of this 

 rather common species. The deep interzooecial avicularia are thin 



F G 



Fig. 31.— Holoporella albikostris Smitt, 1873. A, B. Two opercula, X 85, 



SHOWING variations. C. OPERCULUM OF A SUPERFICIAL ZOOECIUM. Z>. MAN- 

 DIBLE OF AN ORAL AVICULARIUM. E, F. TWO MANDIBLES OF THE INTER- 

 ZOOECIAL AVICULARIA SHOWING VARIATIONS OF THE LUCIDA. G. LARGE 

 MANDIBLE 



and long. The superficial interzooecial avicularia appear as large 

 salient tubes as broad as the zooecia. Our figure represents an 

 ensemble of well-preserved zooecia and superficial avicularia. It is 

 easy to understand that such a spinous and fragile structure is easily 

 broken and that the determination of fossil specimens presents great 

 difiiculties. 



The operculum is very thin, quite transparent, and its preparation 

 is very delicate. Nevertheless we believe that the figures of Busk, 



