DESCRIPTIVE CATALOGUE OF RECENT FORAMINIFERA. 327 



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

 Diameter, about 0.75 mm. ( 3 V inch). 



Locality. — Oft' the west coast of Cuba (station 2352), 403 fathoms. 



Genus DISCORBINA. 



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

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

 flap, the Haps 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 interiorly; sutures a little 

 depressed; aperture large and irregular at the umbilical margin of 

 the last segment. Diameter, about 0.S mm. (^ inch). 



Locality. — Off Carysfort Light, Florida (station 2041), 00 fathoms. 



DISCORBINA ROSACEA d'Orbigny. 

 (Plate 72, fig. 3.) 



Contour lenticular, planoconvex, 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. ( fi V 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. (^ inch). 



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

 2352), 79 to 403 fathoms. 



DISCORBINA BICONCAVA Parker and 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. 

 ((fo "»eh). 



Locality — Gulf of Mexico (station 2400), 109 fathoms. 



