ART. 14 FOSSIL AND RECENT BRYOZOA— CANU AND BASSLER 141 



and to be easily transported by currents. We have found some other 

 fragments coming certainly from more complete colonies. 

 Our living specimens were ovicelled in March and April. 

 Occurrence. — Fowey Light, 15 miles south of Miami, Fla., 40 fms. 

 Albatross Station D. 2387, Gulf of Mexico; 29° 24' 

 00" N.; 88° 04' 00" W.; 32 fms.; sand, gravel, 

 broken shells. 

 Albatross Station D. 2640, Straits of Florida; 25° 05' 



00" N.; 80° 15' 00" W.; 56 fms.; coral sand. 

 Tortugas, 13-29 meters (Osburn); Florida, 79-127 

 meters (Smitt) ; Bermudas, shallow water (Verrill) , 

 Plesiotype. —C&t. No. 7514, U.S.N.M. 



Genus HIPPOTREMA Canu and Bassler, 1927 



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

 The zooecia are piled upon each other in disorder; their frontal is 

 perforated by tremopores. The aperture is formed by a large 

 orbicular anter and by a short poster separated by two cardelles. 

 The operculum does not have lateral linear attachments. 



Genotype. — Eippofrema {Lepralia) jantMna Smitt, 1873. 



Range. — Recent. 



This is the G. janthina group of Waters of which we have published 

 a text figure. ^° The genus differs from Hipp oporidra in the transfor- 

 mation of the pleurocyst into a tremocyst, in the different form of the 

 poster, and in the absence of linear attachments to the operculum. 



The only known species are : 



Hippotrema {Lepralia) ja^ntliina Smitt, 1873, Florida. 



Hippotrema {Lepralia) rotundora Norman, 1909, Madeira. 



Waters, 1899, and Norman, 1909, are not in accord on the character 

 of the second species. 



HIPPOTEEMA JANTHINA Smitt, 1873 



1873. Le-pralia jantMna Smitt, Floridan Bryozoa. KongL Svenska Veten- 

 skaps Akademiens, Handlingar, vol. 11, p. 63, pi. 11, figs. 224, 225. 



1904. Lepralia janthina Osburn, Bryozoa of the Tortugas Islands. Pub= 

 lication Carnegie Institution, Washington, No. 182, p. 213. (No 

 Waters, 1899) (according to Norman). 



Measurements. — Width of aperture =0.11 (Smitt; to 0.12 mm. 



Structure. — The small avicularium is placed in the vicinity of the 

 aperture; it is triangular and erected almost vertically. Contrary 

 to the opinion of Osburn, there are interzooecial avicularia; they are 

 long and thin; their presence is rather rare. 



Biology. — Our living specimen encrusts Stylopoma spongites; it was 

 in reproduction January 17, 1885. 



"Canu and Basslor, 1920, p. 615, fig. 185. 



