KORTH AMERICAN EARLY TERTIARY BRYOZOA. 153 



Group of CALLOPORA TENUIROSTR1S. 

 C'ALLOPORA CUCULLATA, new species. 



Plate 14. fig. 1. 



Description. The zoarium incrusts a species of Idmoiua. The zooecia are 

 elongated, distinct, elliptical; the mural rim is salient, flat, granular, very thin at 

 the top, enlarged below. The opesium is elliptical. The hyperstomial ovicell never 

 closed by the opercular valve, globular, and salient, exhibits a frontal triangular 

 area of greater or less size. The avicularia are interzooecial. dispersed over the 

 zoarium, large, without pivot, and quite acuminate. 



. (Ao=0.20-0.24 mm. . [Z,: =0.32-0.36 mm. 



Measurements. Opesia , . Zooecia , 



|Zo=0.16 mm. lfe=0.20 mm. 



. (Zay=0.30-0.36 mm. [7;o-y=0.14 mm. 



Avicularia , Ovicells , 



\lav=O.W mm. \lov=Q.OS mm. 



Affinities. The ovicell is formed of two calcareous lamellae: the interior 

 lamella is formed of an olocyst identical with the olocyst of the mural rim ; the. 

 superior lamella is a cover like a hood but incomplete and leaves the triangular area 

 referred to above. The size of this area is quite variable. 



In its ovicell this species resembles Callopora aurita Hincks, 1877, considerably, 

 but it differs in its greater zooecial length, and its interzooecial avicularia are as 

 long as the zooecia themselves. 



Callopora cucullata differs from C '. tenuirostris Hincks. 1880, in the triangular 

 area of its ovicell and in its smaller dimensions. 



Occurrence. Lower Jacksonian : 3i miles southeast of Shell Bluff post office, 

 Georgia (very rare). 



ffolotype.Ca.t. No. 63849, U.S.N.M. 



CALLOPORA STIPATA, new species. 



Plate 4, fig. 1. 



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

 separated by a deep furrow; the mural rim is flat, very finely striated, much 

 enlarged at the base ; the gymnocyst is very small and inconstant ; the opesium is 

 oval, very finely denticulated. The ovicell is small, globular, smooth, salient. The 

 interzooecial avicularia are large, very elongated, fusiform or elliptical with two 

 lateral denticles. 



. \ho=0.18 mm. . (7,3=0.30-0.36 mm. 



Measurements. Opesium, A , Zooecia 7 A10 



(0=0.13 mm. |te=0.18 mm. 



. (Zow=0.24-0.36 mm. 

 Avicmaria , 



| tow =0.12 mm. 



Affinities. This species is very characteristic. The avicularia are grouped in 

 distinct but irregular lines : they appear to safeguard the zooecia which they often 

 entirely surround. 



Occurrence. Midwayan (Clayton limestone) : Well at Brunclidge, Alabama 

 (very rare). 



Holotype.Cat. No. 63795, U.S.N.M. 



