168 
BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 
Genotype .— Tremogasterina problematica Canu, 1911. 
Range. —Rocanean, Miocene. 
In 1911 Canu discovered this remarkable and mysterious genus in the Rocanean 
strata of Argentina ; that is to say, at the base of the Eocene. He noted the nature 
of the ovicell in his remarks that it opened in the interior of the zooecium. The 
single described species, Tremogasterina problematica, is insufficiently preserved to 
serve as a genotype, and as the Miocene species here described are much better 
preserved, they will give a clearer idea of the genus. The form of the aperture 
indicates clearly the presence of a compensatrix. Therefore, it is rather probable 
that the enormous frontal pore is an ascopore. 
TREMOGASTERINA HORRIDA, new species.* 
Plate 24, figs. 3, 4. 
Description. —The zoarium is free, bilamellar, with small distorted fronds. 
The zooecia are distinct, very elongate, elliptical, little regular, little convex; the 
frontal is perforated by a large, median orbicular pore, surrounded by a line of 
scattered areolar pores. The apertura is very large, elongate, semielliptical; it 
presents a slight constriction at the lower third, probably at the level of the articu¬ 
lations. The peristome is thick and tuberous. The ovicell is endozooecial, smooth, 
transverse, little salient; the apertura is of the same size as that of the ordinary 
zooecia. Between two apertures, on one or the other zooecium, there is an immense 
triangular avicularium, without pivot with the beak turned toward the top. 
Measurements. —Apertura 
\ha = 0.18-0.20 mm. 
I la = 0.14 mm. 
Zooecia 
X2 = 0.60 mm. 
)z =0.30 mm. 
Opesium of thej hav = 0.14 mm. 
avicularium 1 lav = 0.10 mm. 
Avicularium 
Lav = 0.30-0.40 mm. 
lav = 0.24 mm. 
Affinities. —This species has a disagreeable aspect and its structure is difficult 
to understand. We have only found three small specimens and we have not been 
able to make a good dissection. The ovicell itself was not in condition to be photo¬ 
graphed. If the frontal perforation is an ascopore, the apertura ought not to have 
an operculum moving on a special axis; this is not the case, the proximal border not 
being straight. This perforation corresponds perhaps to a special avicularium. 
Occurrence. —Miocene (Choctawhatchee marl): Jackson Bluff, Ocklocknee 
River, 25 miles southwest of Tallahassee, Florida (rare). 
Holotype. —C^t. No. 68684, U.S.N.M. 
CHEILOPORINA, new genus. 
The ovicell is endozooecial; the apertura of the ovicelled zooecium is very 
large. The frontal is a tremocyst. The apertura bears two cardelles and the 
operculum is narrowed laterally at their level. No separation between the ovicell 
and the zooecium. Twenty-seven tentacles. 
Genotype.—Cheiloporina (Ilippoporina ) circumcincta Neviani, 1896. 
Range. —Jacksonian to Recent. 
6 A second new species Treuiogasterina truncatoros/ris is given on p. 244. 
