NORTH AMERICAN EARLY TERTIARY BRYOZOA. 237 



These micrometric measurements differentiate it clearly from Micropora minu- 

 ticella which is exceptionally small. 



Occurrence. Midwayan (Clayton limestone) : One mile west of Fort Gaines, 

 Georgia (very rare). 



Middle Jacksonian (Castle Haync limestone) : Wilmington, North Carolina 

 (rare). 



Upper Jacksonian (Ocala limestone) : \\ miles above Bainbridge, Georgia; 

 4 miles below Bainbridge, Georgia; 7 miles above Bainbridge, Georgia; Chipola 

 River, east of Marianna, Florida. 



Vicksburgian (Marianna limestone) : West bank of Conecuh River, Escambia 

 County, Alabama (rare); deep well, Escambia County, Alabama; near Claiborne, 

 Alabama (rare) ; Salt Mountain, 5 miles south of Jackson, Alabama (rare). 



Postpliocene : Santa Barbara, California (Gabb and Horn). 



Patagonian: Argentina (Canu). 



Geological distribution. Auversian of France (Canu) ; Priabonian of the 

 Vicentin (Reuss, Waters), of Hungary (Pergens) ; Aquitanian of France (Canu) ; 

 Burdigalian of France (collection Canu) ; Sicilian and Quaternary of Italy 

 (Neviani). 



Habitat. Atlantic: Off France, England. Azore Islands, Madeira and Florida 

 (36-136 fathoms,). Mediterranean (80 meters). Antarctic (500 meters). Pacific: 

 Off Queen Charlotte Island and California (45 fathoms). In the Antarctic the 

 species lives at a temperature of 9 Centigrade. 



Plesiotypes.C&t, Nos. 63803, 63801, U.S.N.M. 



MICROPORA MINUTICELLA, new species. 



Plate 4, fig. 23. 



Description. The zoarium incrusts small shells. The zooecia are small, dis- 

 tinct, separated by a furrow, elongated; the cryptocyst is shallow, very finely 

 granulated : the mural rim is thin, distinct, nearly complete ; the aperture is semi- 

 lunar, transverse, surrounded by a peristome. The ovicell is smooth and endozooe- 

 cial. A pair of very small lateral opesiules is present. 



i ho=0.04: mm. . [Lz = 0.25-0.27 mm. 



Measurements. Aperture , . A ^ Zooecium , nnn 



\7o~0.0tmm. l/s=0.20mm. 



Affinities. This is the smallest of the known species of Micropora. Its anoes- 

 trula, however, is not much smaller than the other zooecia. 



Occurrence. Midwayan (Clayton limestone) : One mile west of Fort Gaines, 

 Georgia (very rare). 



Nolotype.Cat. No. 63S05, U.S.N.M. 



Genus HOPLOCHEILINA Canu, 1911. 



1911. Hoplochellina CANU, Iconnitrapliie ilcs Bryozoaires fossik-s <k' 1'Argentine, pt. 2, Anales 

 del Museo Is'acional de Buenos Aires, vol. 21, p. 261. 



The polypidian convexity is little salient. The opesiules are round, indenta- 

 tions of little depth. The opesium is ogival. The cryptocyst is little deep. The 

 ovicell is endozooecial. There are two large, oral avicularia. 



