NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
425 
functions as if they existed (as in the genus Hippodiplosia) . The proximal 
border of the apertura is straight or somewhat concave. No spines. 
Genotype. — Cyclicopom ( Lepralia ) longipora MacGillivray, 1882. 
Range. — J acksonian-Recent. 
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 band much more cliitinized. 
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 pleurocyst 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 Membranipora tenuirostris 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. 
Measurements. — Apertura 
1 \la— 0.15-0.17 
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 Cyclicopora colum in its much larger dimensions. 
Occurrence. — Middle Jacksonian (Castle Hayne limestone) : Wilmington, 
North Carolina (very rare). 
Holotype. — Cat. 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- 
mm. 
Zooecia 1 
(Zs= 0.80-0.95 mm. 
lfe=0.45 mm. 
