DESCRIPTIVE CATALOGUE OF RECENT FORAMINIFERA. 337 



Family X. NUMMULINID^E. 



Test calcareous and finely tubulated; typically free, polythalamous 

 and symmetrically spiral. The higher modifications all possessing a 

 supplemental skeleton and a canal system of greater or less complexity. 



Subfamily FOI.YSTOMELLIN^C. 



Test bilaterally symmetrical ; nautiloid, lower forms without supple- 

 mental skeleton or interseptal canals ; higher types with canals open- 

 ing at regular intervals along the external septal depressions. 



Genus NONIONINA. 



Supplemental skeleton absent or rudimentary; no external septal 

 pores or bridges; aperture a simple curved slit. 



NONIONINA BOUEANA d'Orbigny. 

 (Plate 79, tig. 5.) 



Oval, compressed, bilaterally symmetrical; composed of numerous 

 long, narrow, curved segments coiled in a close flat spiral, the last con- 

 volution completely inclosing the others; outline smooth; sutures flush; 

 surface granular about the umbilici, which are depressed; no intersep- 

 tal pores. Diameter, about O.G mm. (- 4 -i - inch). 



Locality. Gulf of Tokyo, 9 fathoms. 



NONIONINA SCAPHA Fichtel and Moll. 

 (Plate 80, fig. 1.) 



Oval, compressed, symmetrical, smooth, not granular about the 

 umbilici; segments comparatively few, increasing rapidly in size; face 

 of the terminal segment broad and round. Diameter, about 0.4 mm. 

 (eV inch). 



Localities. Panama Bay, coast of Yucatan, and Gulf of Tokyo 

 (stations 2805, 2358), 9 to 222 fathoms. 



Genus POLYSTOMELLA. . 



Supplemental skeleton, septal bridges, and canal system more or 

 less fully developed ; canals opening externally at the umbilicus and 

 by a single or double row of pores along the siitures. Aperture a 

 v-shaped line of perforations at the base of the septal face. 



POLYSTOMELLA STRIATOPUNCTATA Fichtel and Moll. 



(Plate 80, fig. 2.) 



Discoidal, bilaterally symmetrical.; final convolution incloses all the 

 others; margin rounded; Avails finely perforated ; septal bridges dis- 

 tinct; a single row of pores along the sutures. Diameter, about O.G mm. 

 (/o inch). 



NAT MUS 97 22 



