NORTH AMERICAN EARLY TERTIARY BRYOZOA. 425 



function- ;is if they existed (as in the genus flipped ij>l(i*!<i.)- The proximal 

 border of the apertura is straight or somewhat concave. No spines. 



Genotype. Cyclicopora (Lepralia) longipora MacGillivray. 1882. 



Range. Jacksonian-Eecent. 



The simplicity of the structure of this genus has been much exaggerated on 

 account of an incomplete observation of the operculum, the ovicell, and the frontal. 

 The axis of rotation of the operculum is at the middle of the aperture; its anterior 

 part is reenforced by a baud much more chitinized. 



Cyclicopora polaris Waters, 1904, belongs to a closely related genus; the oper- 

 culum bears indeed the same distal sclerite, but its form is different, the frontal is 

 a pleuroc3 - st proceeding from lateral areolae, and there are some spines; this is 

 the genus Kymella described on page 428. 



Hincks has introduced Cyclicopora into a special family, the Cyclicoporidae. 

 This family is perhaps really a good one; the frontal of the two known genera 

 appear to be formed by the consolidation of the primitive costules. as the figures 

 of Hennig and of Waters, which we reproduce, seem to prove. Finally, the oper- 

 culum has a broad, thickened border, reminding us of the. opercula of some Mem- 

 branipora, such as Meiribranipora tcnuirostms Hincks. 1880. 



CYCLICOPORA FISSURATA, new species. 



Plate 55, fig. 7. 



Description. The zoarium is unilamellar and creeps on algae. The zooecia 

 are elongated, distinct, elliptical: the frontal is convex and covered by very large 

 tremopores. The apertura is semilunar with a proximal border somewhat concave; 

 the peristome is wide, complete, hardly salient. On each side of the apertura there 

 are two avicularia, elongated, thin, adjacent to the peristome, the beak directed 

 toward the top. 



fAa=0.20mm. . fZs=0.80-0.95mm. 



Measurements. Apertura , _.,. Zooecia,, 



Ua=0.15-0.17 mm. \lz=QA5 mm. 



Affinities. The avicularia are seen in perspective; they have the aspect of 

 two fissures in the zooecia. 



This species differs from Cyclicopora longipora MacGillivray, 1882, in its 

 enormous tremopores and its two large oral avicularia. 



It differs from Cyclicoporn colum in its much larger dimensions. 



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

 North Carolina (very rare). 



Holotype.Cak. No. 64113, U.S.N.M. 



CYCLICOPORA COLUM. new species. 

 Plate 87, fig. 15. 



Description. The zoarium incrusts bryozoa. The zooecia are elongated, dis- 

 tinct, separated by a deep furrow, the frontal is convex and covered with large 

 tremopores, widely spaced. The aperture is semielliptical or semilunar; the proxi- 



