BRYOZOAN FAUNA OF VINCENTOWN LIMESAND 67 



It is so irregular in form and dimensions that we must suppose the 

 opercular valve does not correspond to it exactly. It is therefore 

 more an opesium in which the distal portion only was covered by 

 the opercular valve. 



The arrangement of the apertural bar causes us to believe that 

 the zooecium was covered by the ectocyst and the great importance 

 of the epicalcification confirms this hypothesis, since it cannot occur 

 above the ectocyst. 



The ovicells are very rare, although we have numerous fragments 

 of zoaria. The colonies must have been very large but relatively 

 fragile because of the slight thickness of the fronds. 



Occurrence. — Vincentown limesand : Mullica Hill, Vincentown 

 (common), and near Blackwoodstown (rare), N.J. ; Noxontown 

 Millpond, Del. (rare). 



Plesiotype.— U.S.N.M. No. 73905. 



DIACANTHOPORA DISTANS Gabb and Horn, 1862 



Plate 14, Figures 8, 9 



1S62. Escharipora distans Gabb and Horn, Journ. Acad. Nat. Sci. Philadelphia, 



ser. 2, vol. 5, p. 148, pi. 20, fig. 32. 

 1922. Diacanthopora distans Lang, Catalogue of Cretaceous Bryozoa in the 



British Museum, vol. 4, pt. 2, p. 235 (bibliography). 



Description. — The zoarium encrusts fragments of sea urchins, 

 shells, and other Bryozoa. The zooecia are distinct, elongated, 

 elliptical, united together by an intense calcification forming a thick 

 mural rim, salient; the frontal is little convex and formed of 8 to 

 10 separated costules attached only at their extremity to a salient 

 median crest; each costule is decorated with a proximal pelma; the 

 apertural bar is broad, distinct, little concave, of the same structure 

 as the costules. The apertura is suborbicular with the proximal 

 border straight or a little concave ; the distal peristome is thin, with 

 four spines on the little calcified zooecia, thick and smooth on the 

 others. The ovicell is hyperstomial, not closed by the operculum, 

 resting on the especially developed gymnocyst of the distal zooecium, 

 which thus becomes longer; it is surrounded by a thick circle of 

 frontal epicalcification, at the center of which is a shallow circular 

 area. Two avicularia are placed symmetrically on each side of the 

 aperture; they are triangular, oblique, with rounded beak, oriented 

 distally toward the longitudinal axis of the zooecium. 

 Measure m en ts. — 



Lz = 0.6 mm and 0.85 mm. . |7m=0.15mm. 



Zooecium (ovicelled). ^ [/a=0.15mm. 



/2 = 0.35mm. 



15 zooecia in 4 sq. mm. 



