328 REPORT OF NATIONAL MUSEUM, 1897. 



Genus PLANORBULINA. 



Test normally adherent; compressed or complanate segments very 

 numerous, commencing growth on a spiral plan, subsequently becom- 

 ing more or less cyclical; lipped apertures of the individual segments 

 opening externally at the periphery. 



PLANORBULINA ACERVALIS Brady. 

 (Plate 72, fig. 7.) 



Discoidal, thin, the attached side flat and smooth, the inferior face 

 roughened by the projection of numerous irregular inflated segments 

 over the whole surface; walls coarsely porous; apertures peripheral. 

 Diameter, 1.5 to 2.5 mm. (-^ to -^ inch). 



Locality. Gulf of Mexico (station 2399), 190 fathoms. 



PLANORBULINA MEDITERRANENSIS d'Orbigny. 

 .(Plate 72, fig. 6.) 



A thin, flat, nearly circular shell, when living usually attached to 

 some foreign body, composed of numerous segments arranged in a sin- 

 gle layer more or less distinctly spiral; attached surface nearly flat, 

 opposite surface lobulated; periphery irregular; segments inflated, 

 slightly embracing, very conspicuously and profusely perforated; 

 sutures depressed; apertures at the extremity of each segment, sim- 

 ple, with a raised lip. Diameter, about 1 mm. (^ inch). 



Locality. A single specimen obtained in the Gulf of Mexico (station 

 2377), 210 fathoms. 



Genus PULVINULINA. 



Test rotaliform, superior side usually thickest; shell finely porous; 

 segments fewer than in other rotalinse; aperture typically a large slit 

 at the base of the umbilical margin of the last segment. 



PULVINULINA REPANDA Fichtel and Moll. 

 (Plate 72, fig. 8.) 



Lenticular, about equally convex on both faces; peripheral margin 

 subacute, limbate; sutures broad, conspicuous by reason of their glassy 

 clearness, limbate on both faces; umbilicus filled smoothly with hyaline 

 shell substance; aperture as usual, 



Locality. Arrowsmith Bank, coast of Yucatan (station 2354), 130 

 fathoms. 



PULVINULINA PUNCTULATA d'Orbigny. 

 (Plate 73, fig. 1.) 



Contour round or oval ; superior face convex, inferior face depressed 

 at the center; margin rounded; segments rather numerous, somewhat 

 inflated, in about three convolutions ; sutures slightly depressed; umbili- 



