168 BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 



t 



Genotype. — Tremogasterina proUematica 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 natui-e 

 of the ovicell in his remarks that it opened in the interior of the zooecium. The 

 single described species, Tremogasterina proUematica, 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 HOKRIDA, 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. 



,, . A ^ f^a = 0.18-0.20 mm. „ . fL2 = 0.60 mm. 



Measurements. — Apertura ^ . , , Zooecia , . __ 



^ ua = 0.14mm. fe =0.30 mm. 



Opesium of the 

 avicularium 



hav = 0.l't mm. 



Za'!; = 0.10 mm. 



. . , . fia'y = 0.30-0.40 mm. 

 Avicularium , „ „ , 



i 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 

 a*i 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 oviceUed 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 (Hippoporina) circumcincta Neviani, 1896. 



Range. — Jacksonian to Recent. 



•A second new species TreuiogiuUrlna tmieatoroslm is given on p. 244. 



