278 REPORT OF NATIONAL MUSEUM, 1897. 



Genus THURAMMINA. 



Test typically consisting of a single Orbulina-like chamber with 

 several mainmillate apertures. 



THURAMMINA PAPILLATA Brady. 

 (Plate 22, fig. 1.) 



Test spherical, with very thin walls constructed of fine sand grains 

 firmly and smoothly cemented, inclosing a single undivided chamber. 

 The surface is studded with more or less numerous nipple-like proc- 

 esses, each of which terminates in a simple aperture 5 color, various 

 shades of brown. Diameter, O.G to 1.5 mm. (-^ to -^ inch). 



Localities. South of Long Island, Gulf of Mexico, southeast Georges 

 Bank, coast of Brazil (stations 2225, 2383, 2385, 2570, 2760), 730 to 2,512 

 fathoms. 



THURAMMINA FAVOSA new species. 

 (Plate 21, fig. 2.) 



Test spherical 5 walls very thin, arenaceous, brown ; surface orna- 

 mented with a network of thin prominent ridges extending uniformly 

 over the whole test, forming hexagonal pits; cavity smooth; apertures 

 numerous, small, at the end of short tubular processes from some of the 

 points of junction of the ridges. Diameter, about 0.8 mm. (-^ inch). 



Locality. Gulf of Mexico (stations 2374, 2394), 26 and 420 fathoms. 



THURAMMINA CARIOSA new species. 

 (Plate 22, fig. 2.) 



Spherical; surface rough, as if eroded; walls rather thick, cavernous; 

 cavity globular, smooth; apertures not tubular; color a dirty brown. 

 Differs from T. favosa in the thicker walls and coarser structure, the 

 eroded rather than reticulated surface, the cavernous walls, and the 

 nontubular orifices. Diameter, about 1 mm. (-^ inch). 



Locality. Gulf of Mexico (stations 2385, 2394), 420 and 730 fathoms. 



Genus AMMODISCUS. 



Test free, formed of a tube coiled upon itself in various ways ; some- 

 times constricted at intervals, never truly septate. 



AMMODISCUS INCERTUS d'Orbigny. 

 (Plate 23, fig. 2.) 



A thin disk, concave on both faces, composed of numerous convolu- 

 tions of a narrow, nonseptate tube, whose diameter increases very 

 gradually from beginning to end; walls arenaceous, smooth; color in 

 various shades of brown; aperture the unconstricted end of the tube. 



