150 BULLETIN 106, UNITED STATES NATIONAL, MUSEUM. 



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

 North Carolina (very rare). 



Holotype. Cat. "NO. 63923, U.S.N.M. 



CALLOPORA FILOPARIETIS, new species. 

 Plate 29, fig. 4. 



Description. The zoarium incrusts pebbles and Cellepores. The zooecia are 

 elongated, distinct, elliptical, variable : the mural rim is very thin, filiform, salient, 

 convex. The opesium is entire, medium, and of the same form as the zooecia. The 

 ovicell is hyperstomial, never closed by the opercular valve, smooth, salient, trans- 

 verse. The avicularia are small, very pointed, nearly perpendicular to the zoarial 

 plane appearing to be interjected between the opesia. 



. Ao=0.40-0.45 mm. , thov=0.15 mm. 



Measurements. Opesia 7 Ovicells L 



fo=0.26 mm. [1ov=Q.20 mm. 



Affinities. This species differs from the recent Membranipora macilenta 

 Jullien, 1882, in which the walls are very thin, by its much smaller micrometric 

 dimensions and in the form of its mural rim. 



The species having thin mural rims are not rare; they can be determined readily 

 only if they bear ovicells and avicularia. 



Occurrence. Lower Jacksonian (Moodys marl) : Jackson, Mississippi (rare). 



Holotype. Cat. No. 63921, U.S.N.M. 



CALLOPORA INGENS. new species. 

 Plate 29, fig. 3. 



Description. The zoarium incrusts rocks. The zooecia are elongated, little 

 distinct, separated by a very small furrow, nearly hexagonal ; the mural rim is but 

 little salient, convex, thin at the top, enlarged below, finely granulated ; the opesium 

 is elliptical and finely crenulated. The hyperstomial ovicell is small, globular and 

 projects considerably. The avicularium is very small, salient, oblique, the point 

 below. 



. (Ao=(UO-0.44 mm . I 0=0.56-0.60 mm. 



Measurements. Opesia, _ Zooecia, ... 



(?0=0.24 mm. |fo=0.40 mm. 



Affinities. The avicularium is placed in a small triangular, interopesial cavity, 

 the walls of which are often distinct. 



This species bears considerable resemblance to Callopora dumerilii Audouin, 

 1826, differing from it only in its much larger dimensions and the inconstancy of 

 its small avicularia. 



Occurrence. Lower Jacksonian (Moodys marl): Jackson, Mississippi (very 

 rare). 



riolotype.C&t. No. 63920, U.S.N.M. 



