NORTH AMERICAN EARLY TERTIARY BRYOZOA. 413 



Occurrence. Vicksburgian (" Chimney rock " of Marianna limestone) : One 

 mile north of Monroeville, Alabama (rare). 



In Europe this variety has been observed since the Helvetian in the same 

 countries as the type species itself, but it has never been mentioned as recent. 



It is remarkable that Peristomella c.occinea Abildgaard, 1805, has disappeared 

 from the western Atlantic and from' the Gulf of Mexico since the commencement 

 of the Miocene. 



Plcsiotype.Cat. No. 64282, U.S.N.M. 



PERISTOMELLA LATICELLA, new species. 



Plate 54, figs. 5-7. 



Description. The zoarium incrusts shells and bryozoa or creeps over algae. 

 The zooecia are distinct, wide, aliform; the frontal is convex, smooth, surrounded 

 by a line of crowded areolae; it is formed of an olocyst covered over and intimately 

 united with a pleurocyst. The aperture is very oblique (about 45) semilunar, 

 transverse, hidden under a salient and wide mucro; the proximal part of the 

 peristome bears four large spines. The ovicell is hyperstomial, but embedded in 

 the distal zooecia ; it is salient, wide, transverse, globular, smooth, surrounded by 

 very small areolae, identical with the frontal. The two avicularia are large, tri- 

 angular, with pivot, transverse, symmetrically placed. The ancestrula is small. 

 Measurements. External aperture lpi=0.15 mm. 



[7.3=0.55-0.60 mm. 



Zooecia lfe=0.50-0.60mm. 



Affinities. The analogy of the ovicellarian walls with the frontal is easy to 

 observe on this species (fig. 6) ; the pleurocyst is more or less thick. The ances- 

 trula is a small ordinary zooecium. 



In its form and general aspect this species is close to Peristomella alifera Eeuss, 

 1869, from the Vicentin. It differs from it in its incrusting and non-bilamellai 

 zoarium and in its wide zooecia. 



It differs from Peristomella coccinca Abildgaard. 1805, in its transverse ovicell, 

 the entire absence of a false peristomie, its much wider zooecia (7s=0.50-0.60mm. 

 and not 0.30 mm.), and the presence of six spines (and not four). 



Tt differs from Perixtomella erect a, and P. fulf/urans Manzoni, 1870; in its 

 avicularia disposed transversely and not longitudinally. 



Occurrence. Lower Jacksonian (Moodys marl) : Jackson, Mississippi (rare). 

 Middle Jacksonian: Wilmington, North Carolina (very common); near Lenuds 

 Ferry, South Carolina (rare) ; 18 miles west of Wrightsville, Johnson County, 

 Georgia (very rare) ; 3i miles north of Grovania. Georgia (very rare). 



Upper Jacksonian (Ocala limestone) : "West bank of Sepulga River, Escambia 

 County, Alabama (common). 



Cotypes.Cnt. No. 64107, U.S.N.M. 



PERISTOMELLA ERECTA. new species. 



Plate 87, figs. 16, 17. 



Description. The zoarium incrusts shells. The zooecia are distinct, elongated, 

 elliptical; the frontal is convex, smooth, bordered by areolae and covered by a thick 



