NORTH AMERICAN EARLY TERTIARY BRYOZOA. 415 



The texture of the frontal of the ovicell is identical, but the areolae are much 

 smaller. In front of the ovicell 2 or 4 spines often persist. The direction of the 

 avicularia is not very constant; they are sometimes somewhat oblique. 



Affinities. This is the American representative of Peristomella fulgurans 

 Manzoni, 1870, of the Italian Pliocene. Our species differs from it in a lesser 

 convexity of the frontal and in the avicularia, which are straight (and not some- 

 what arched) and which never touch the peristome. 



This species differs from Peristomella laciniata Seguenza, 1879, in the absence 

 of a false peristomie and in the elliptical, elongated form of its external aperture. 



It differs from Perist&mdla laticclla and P. coccinea Abildgaard, 1805, in its 

 avicularia placed longitudinally (and not transversally). 



Occurrence. Vicksburgian (Marianna limestone) : Near Claiborne, Monroe 

 County, Alabama. 



Cotypes.Cnt. No. 64284, U.S.N.M. 



PERISTOMELLA FALCIFERA, new species. 



Plate 54, figs. 8-10. 



Description. The zoarium incrusts shells. The zooecia are large, elliptical, 

 erect; the frontal is very convex, smooth, surrounded by a double line of very 

 small areolae, quite crowded; it is terminated distally by a salient mucro, bifid, 

 oblique. The peristome is quite prominent, thick, garnished with six spines; the 

 locella is very large; the apertura (in the interior) is suborbicular, oblique, entirely 

 hidden by the mucro. The ovicell is very large, globular, quite salient, smooth; 

 it is hyperstomial, placed on the distal zooecium; it opens into the locella by a 

 large orifice, facing the mucro. On each side of the apertura there are two long 

 falciform avicularia, parallel to the zooecial axis, the beak above. 



. rZs=0.75mm. 

 Measurements. Zooecia {^ __ 



lfe=0.60mm. 



Affinities. In the disposition of the avicularia, this species is near to 

 Peristomella fulgurans, but differs in the form of the straightened avicularia and 

 its larger micrometric dimensions. 



It differs from Lcpralia complicates Keuss, 1847, in its much larger bifid mucro 

 hiding the apertura. 



The convexity of the zooecia gives to the interior of the zooecia a very peculiar 

 geometric aspect; the locella appears as a simple slit between the zooecia and the 

 ovicell (fig. 10). 



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

 North Carolina (very common). 



Cotypes.Cat. No. 64108, U.S.N.M. 



Genus EXOCHELLA Jullien, 1888. 



1S88. Exochella JTJLT.IEN, Mission scientifique du Cap Horn, vol. 6, Zoologie Bryozoaires, 

 p. 55. 



The aperture is oblique without lyrula, cardelles or rimule. The ovicell is 

 hyperstomial and imbedded in the distal zooecia. It opens above the aperture and 



