580 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



PERIGASTRELLA OVOIDEA Canu and Hassk-r, 1917. 



Plate 73, figs. 2-4. 



1917. Perigastrella ovoidea CANU and BASSLEK, Synopsis of American Early Tertiary Cheilo- 

 stome Bryozoa, Bulletin 9C, United States National Museum, p. 68, pi. 6, fig. 8. 



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

 large, ovoid; the frontal is very convex, bordered by very small areolar pores and 

 formed of a very finely granular pleurocyst almost smooth, The apertura, almost 

 invisible exteriorly, is trapezoidal and oblique; the peristomie is deep; the peristome 

 is very oblique and bears six to eight spines; it is sometimes interrupted in front, 

 but more often it bears a salient mucro, oblique or erect, hiding more or less the 

 apertura ; there is a small lyrula in the apertura. The ovicell is small, salient, 

 globular, almost entirely detached from the distal zooecium ; it is hyperstomial and 

 recumbent; its frontal is finely granular like the zooecja. The ancestrula is very 

 small, but identical in form with the other zooecia. 



,, |Aa=0.05mm. . fZ2=0.75-O.SOmm. 



Measurements. Apertura 7 Zooecia , __- 



Ua=0.08-0.10 mm. Us=0.50 mm. 



x. This beautiful species is quite recognizable by its very large zooecial 

 convexity. It differs from Perigastrella semierecta Koschinsky, 1885, in the presence 

 of spines and in its somewhat larger dimensions. 



It differs from Perigastrella oscitans in its very small and nearly invisible 

 areolae, its large frontal convexity, and its peristomice, three times smaller, and 

 in its oral lyrula. 



It also resembles the ancestrular zooecia of Perigastrella cycloris Gabb and 

 Horn, 1862, but differs in the apertura, which bears a lyrula and no cardelles. 



Occurrence. Middle Jacksonian: Eutaw Springs, South Carolina (common). 



Upper Jacksonian (Ocala limestone) : Plant System Railroad wharf at Bain- 

 bridge, Georgia (common) ; Old Factory, 1| miles above Bainbridge, Georgia 

 (rare)* Keel Bluff, on Flint River, 7 miles above Bainbridge, Georgia (rare) : west 

 bank Sepulga River, Escambia County, Alabama (rare) ; Chipola River, east of 

 Marianna Jackson County, Florida (very rare). 



Vicksburgian (Marianna limestone) : Well, Escambia County, Alabama. 



Cotypes.Czt. No. 62613, U.S.N.M. 



PERIGASTRELLA MAXILLA, new species. 



Plate 73, figs. 5-7. 



Description. The zoarium incrusts shells and other bryozoa. The zooecia are 

 distinct, short, ovoid, erect; the frontal is very convex, almost smooth, surrounded 

 by minute areolae, revealed only by some scarcely visible roughnesses. The aper- 

 tura is deep, oblique, trapezoid, with a straight or somewhat convex proximal 

 border; the peristomie is tubular, large; it is terminated by a peristome with 

 usually eight spines and by a very large, rounded, salient, erect mucro, exposing 

 to view the apertura and almost invariably depressed on the frontal. The ovicell 



