NORTH AMERICAN EAKLY TERTIARY BRYOZOA. 577 



PERIGASTRELLA HEXAGONALIS. new species. 



Plate 72, fig. 10. 



Description. The zoarium incrusts bryozoa. The zooecia are large, distinct, 

 hexagonal; the frontal is little concave and surrounded by a double row of quite 

 crowded areolae ; it is formed of a granular pleurocyst. The apertura is transverse, 

 oblique, trapezoid, little visible exteriorly; the peristome is little salient, oblique 

 with an inferior lip in the form of a mucro, which is elevated and prominent. The 

 ovicell is small, transverse, globular, granular; it is hyperstomial and recumbent. 



,, |Aa=O.OS-0.10mm. . [Z,3=0.80mii.. 



Measurements. Apertura Zooecia 7 A _ A 



- Us=0.70-0.80mm. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : Wilmington, 

 North Carolina (rare). 



Holotype.Czt. No. 64193, U.S.N.M. 



PERIGASTRELLA RHOMBOIDALIS, new species. 



Plate 72, fig. 11. 



Description. The zoarium is bilamellar; the two lamellae, back to back, are 

 inseparable. The zooecia are distinct, large, elongated, rhomboid 'al; the frontal 

 is convex, surrounded by a double line of small triangular areolae and formed of 

 a finely granular pleurocyst. The peristomice is semilunar, transverse, complete, 

 with a concave proximal border; the peristome is thin, sharp, little salient. The 

 ovicell is small, transverse, little salient, finely granular; it is always closed by the 

 operculum. 



-., fha=0.l6mm. . \Lz= 1.00-1.20 mm 



Mcamrements. Apertura \ 7 Zooecia 7 



Ua=0.22-0.24 mm. Us=0.60-O.SOmm. 



Affinities. The figured specimen only has been found. It appears to repre- 

 sent a type rather divergent in the genus. We believe in making a new genus only 

 when the material is sufficient. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : Wilmington, 

 North Carolina (very rare). 



Holotype. Cat.' No. G4104, U.S.N.M. 



PERIGASTRELLA CYCLORIS Gabb and Horn, 18C2. 

 Plate 72. figs. 12-14. 



1862. Cellcpnra cyclorig GABB and HORN, Monograph Polyzoa Secondary and Tertiary forma- 

 tions of North America, Journal Academy Natural Sciences, Philadelphia, ser. 2. 

 vol. 5, p. 127, pi. 19, fig. 9. 



1890. Ccllepnra cycloris DE GREGORIO, Monograph Fauna Eocenique de 1'Alabama, Annales 

 Geologie et Paleontologie, Livr. 7 and 8, p. 247, pi. 43, fig. 1. 



Desc/ription. The zoarium incrusts shells and bryozoa. The zooecia are dis- 

 tinct, large, hexagonal ; the frontal is very convex and surrounded by a triple 

 row of very small areolae; it is formed of a smooth or very finely granular pleu- 



55899 19 Bull. 106 - 37 



