426 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
mal border is straight or somewhat concave. The ovicell is globular, salient, cov- 
ered with smaller tremopores than those of the frontal; it is hyperstomial and 
always closed by the operculum. One of the lateral tremopores, near the aperture, 
transforms itself into a small avicularium, simple, somewhat salient, and elliptical. 
Measurements. — Aperture 
I Aa=0. 12-0.14 mm. 
I la =0.14-0. 16 mm. 
Zooecia 
Lz= 0.55—0.60 mm. 
lz=0A0 mm. 
Affinities . — This species differs from Cyclicopora longipora MacGillivrav, 1882, 
in its large tremopores which give it the aspect of a colander. 
It differs from Cyclicopora fissurata in its much smaller dimensions and the 
absence of elongated, lateral avicularia. 
Occurrence . — Vicksburgian (“Chimney rock” member of Marianna lime- 
stone) : One mile north of Monroeville, Alabama (very rare). 
Holotype. — Cat. No. 64283, U.S.N.M. 
CYCLICOPORA SPONGIOPSIS De Gregorio, 1890. 
Plate 8S, figs. 8-16. 
1890. Eschara spongiopsis De Gregorio, Monograpliie de la Faune Eocenique de Alabama, 
Annales Geologie et de Paleontologie, Livr. 7, 8, p. 241, pi. 40, fig. 2. 
Descnption . — The zoarium is unilamellar, cylindrical, hollow; it surrounds 
the radicells of small algae. The zooecia are very little distinct, elongated, fusi- 
form; the frontal is little convex, very thick and formed of a tremocyst with large 
tubular pores resting on a very thin olocyst. The apertura is oval, at the base of 
a deep peristomie ; the peristome is smooth, not salient, and bears from 1 to 4 simple 
avicularia. The ovicell is hyperstomial, buried in the distal zooecia; it opens into 
the peristomie, it is ornamented with large pores analogous to those of the frontal. 
Measurements. — Apertura 
ha=0 . 20 mm. 
la=0 . 15 mm. 
Zooecia 
j Zs=0.60-0.70 mm. 
11,3= 0.50 mm. 
Variations . — There are occasionally some zooecia bordered by a prominent 
thread (fig. 14). The number of small simple, peristomial avicularia is quite 
variable; sometimes one (fig. 15) sometimes 3 or 4 (fig. 10). The frontal walls 
are very thick and the tubules themselves have thick walls. In the transversal 
sections (fig. 9) this same phenomenon is quite visible. The tangential section 
(fig. 13) shows the large frontal tremopores and the black, sinuous lines of inter- 
section with the olocyst. 
Affinities. — This species resembles much the young zoaria of Porella crassoparies 
which surround also the small algae and their distinction is often quite difficult ; it 
differs from the latter in the complete absence of the median avicularium. 
It seems to us that this species resembles the figure given by De Gregorio of 
his Eschara spongiopsis , but we have not been able to check this observation with 
his type. 
Occurrence . — Vicksburgian (Marianna limestone) : One mile north of Monroe- 
ville, Alabama (very common) ; near Claiborne, Monroe County, Alabama (com- 
mon). 
