"90 PEOCEEDINGS OF THE NATIONAL. MUSEUM vol.72 



Genus GEMELLIPORELLA Canu and Bassler, 1920 



The ovicell is hyperstomial and not closed by the operculum. The 

 frontal is an olocyst bordered by areolar pores and covered by a 

 •granular pleurocyst. There are oral avicularia. 



Genotype. — Gemelliporella vorax Canu and Bassler, 1923. 



Range. — Miocene — Recent. 



Gemelliporella asper and G. vorax Canu and Bassler, 1923, belong 

 to this genus. In 1923 we were deceived by the aspect of the aper- 

 ture of the fossil specimens, but an examination of the recent speci- 

 anens enables us to correct this false interpretation. 



GEMELLIPORELLA ASPER Canu and BasBler 1923 



Plate 10, Figure 1 



1923. Gemelliporella asper Canu and Bassler, North American Later Ter- 

 tiary and Quaternary Bryozoa. Bull. 125, U. S. National Museum, 

 p. 110, pi. 18, figs. 5, 6. 



,, ^ A X [^a = 0.12-0.15 mm. 



Measurements. — Apertureu „ ^^ « ■,/^ 



^ Ua. = 0.08-0.10 mm. 



„ . (Lz = 0.50 mm. 

 Zooecia|^^^Q^Q_Q^g mm. 



Structure. — Like the frontal, the ovicell is formed by an olocyst 

 surmounted by a pleurocyst, but the latter is incomplete and leaves 

 in front a small semicircular cicatrix. The small oral avicularium is 

 elliptical and little salient ; the large zooecial avicularium is arranged 

 laterally; it is salient and its mandible is wide and horny; the pivot 

 bears a very characteristic distal tooth. The areolar pores are large 

 and scattered from each other. 



Our recent specimens are somewhat less calcified than the fossils. 

 Their large avicularium is much smaller than that in specimens from 

 the Miocene but it is equal to that of the Pliocene examples. 



Biology. — The great development of the avicularia seems to indi- 

 cate rather calm waters. Our recent specimens encrust nullipores; 

 the fossils encrusted oysters. 



Occurrence. — Albatross Station D. 2322, north of Cuba; 23° 10' 

 54'' N.; 82° 17' 45" W.; 115 fms.; coral. 



Geologic distribution. — Miocene and Pliocene of Florida and South 

 Carolina. 



Plesiotype.—C&t. No. 7533, U.S.N.M. 



Genus STYLOPOMA Levinsen, 1909 



Levinsen, 1909, published his doubt as to the validity of this 

 genus and even suppressed it. According to his ideas, the passage 

 of the eggs is a function which each species operates differently and 



