DESCRIPTIVE CATALOGUE OF RECENT FORAMINIFERA. 327 



porous ; aperture of each chamber opens into the central vestibule. 

 Diameter, about 0.75 mm. (^ 2 - inch). 



Locality. Off the west coast of Cuba (station 2352), 463 fathoms. 



Genus DISCORBINA. 



Test free or adherent, rotaliform ; plano-convex or trochoid ; rarely 

 coinplanate; aperture an arched slit, often protected by an umbilical 

 flap, the flaps sometimes forming a whorl of subsidary chambers. 



DISCORBINA GLOBULARIS d'Orbigny. 

 (Plate 72, fig. 2.) 



Discoidal, thick, the superior face quite convex, the inferior only 

 slightly so; segments somewhat inflated, finely perforated, hyaline, all 

 visible superiorly, only the last convolution inferiorly; sutures a little 

 depressed; aperture large and irregular at the umbilical margin of 

 the last segment. Diameter, about O.S mm. (fa inch). 



Locality. Off Carysfort Light, Florida (station 2641), 60 fathoms. 



DISCORBINA ROSACEA d'Orbigny. 

 (Plate 72, fig. 3.) 



Contour lenticular, plano-convex, peripheral margin rounded; com- 

 posed of about three convolutions of six segments each ; surface smooth 

 and polished; sutures distinct but not depressed ; color, pale brown ; 

 aperture a narrow arched slit at the umbilical margin of the final seg- 

 ment. Diameter, about 0.4 mm. (-fa inch). 



Locality. Coast of Alaska, station unknown. 



DISCORBINA BERTHELOTI d'Orbigny. 

 (Plate 72, fig. 4.) 



Discoidal, thin, plano-convex; the superior convex face somewhat 

 flattened at the center, peripheral margin sharp ; outlines of the seg- 

 ments very distinct; sutures a little depressed, and thickened with 

 transparent shell- substance; later segments moderately inflated ; walls 

 finely but distinctly perforated. Diameter, about 0.4 mm. (fa inch). 



Localities. North Atlantic and Gulf of Mexico (stations 2212, 2313, 

 2352), 79 to 463 fathoms. 



DISCORBINA BICONCAVA Parker ana Jones. 

 (Plate 72, fig. 5.) 



Circular, flattened on both faces; peripheral margin square or slightly 

 concave; coarsely perforated ; sutures on the superior face between the 

 earlier segments raised into prominent, thin, square-edged, wavy ridges; 

 on the inferior face only slightly limbate. Diameter, about 0.4 mm. 

 (fa inch). 



Locality Gulf of Mexico (station 2400), 169 fathoms. 



