BRYOZOAN FAUNA OF VINCENTOWN LIMESAND 25 



ALLANTOPORA ANNULOIDEA Ulrich and Bassler, 1907 



Plate 4, Figures 3-5 



1907. Membranipora annuloidea Ulrich and Bassler, in Weller, Geol. Surv. 

 New Jersey, Paleontology, vol. 4, p. 335, pi. 23, fig. 18. 



Description. — The zoarium encrusts the debris of shells and 

 ramose Bryozoa. The zooecia are distinct, separated by a deep 

 furrow, somewhat elongated, pyriform; the gymnocyst is short, 

 smooth, convex, thick, more or less narrowed in the proximal por- 

 tion. The termen is thick, rounded, finely granular, and bears five 

 pairs of large hollow spines. The opesium is anterior, elongated, 

 elliptical, or oval. The ovicell is hyperstomial, not closed by the 

 operculum, globular, smooth. The ancestrula is a small ordinary 

 zooecium. 



Measurements. — 



„ \Lz = 0.55-0.65 mm. „ . [7^ = 0.3-0.35 mm. 



Zooecium { 7 Opesium 7 __ __ K 



| lz = 0.4r-0A5 mm. l [ lo = 0.2-0.25 mm. 



16 or 17 zooecia in 4 sq. mm. 



Structure. — The zooecial structure of this species is exactly that 

 of Allantopora irregularis Gabb and Horn, 1860, the same form, 

 same gymnocyst, same spines, and same ovicell. The single dif- 

 ference is in the nature of the zoarium, which is multiserial and 

 not uniserial. It is difficult to see in this slight difference a generic 

 character. Almost all the recent uniserial species sometimes exhibit 

 multiserial zoaria. The cells approaching each other become united 

 and form an ensemble exactly like the colonies of other multiserial 

 species. Dietellae, however, are never present, which is exactly 

 the case here. Regenerated zooecia are abundant. There is often 

 an eleventh spine on the proximal border of the termen. 



Affinities. — We cannot class this species in PyruleJla Harmer, 

 1926, for in that genus the ovicell is closed by the opercular valve. 

 Callopora sexspinosa Canu and Bassler, 1920, from the Midway an 

 of Alabama has an identical structure and should be placed in the 

 same genus. 



Occurrence. — Vincentown limesand : Vincentown, N.J. (rare). 



Holotype and plesiotype. — U.S.N.M. No. 52600. 



Genus PERIPOROSELLA Canu and Bassler, 1917 



PERIPOROSELLA(?) PLEBEIA Gabb and Horn, 1862 



Plate 5, Figures 1-3 



1862. Membranipora plcbcia Gabb and Horn, Journ. Acad. Nat. Sci. Phila- 

 delphia, ser. 2, vol. 5, p. 158, pi. 20, fig. 43. 



1907. Membranipora plebeia Ulrich and Bassler, in Weller, Geol. Surv. New 

 Jersey, Paleontology, vol. 4, p. 334, pi. 23, fig. 17 (bibliography). 



