222 THE FOEAMINIFEEA 



Genus Fiiipertia, W.\llich. 



Test columnar, growing attached by a slightly 

 spreading base ; segments numerous, spirally 

 arranged ; aperture at the inner margin of the 

 terminal segment. Becent. 



Example. — -i?. stabilis, Wallich, ' Ann. and Mag. 

 Nat. Hist.' ser. 4, vol. xix. 1877, p. 501, pi. xx. 



This species exists in great abundance in the 

 colder area of the Faroe Channel, in 632 fathoms. 

 It has been found in other localities, but very 

 sparingly, liecent. (Plate 12, fig. K.) 



Genus PulvinuUna, Paekee and Jones. 



Test Kotaliform, superior side usually thickest ; 

 shell with rare exceptions very finely porous ; 

 segments fewer in number than in the other 

 RoTALiiN.E. Shell-thickening usually taking the form 

 of external sutural limbation. Aperture typically a 

 large slit at the base of the umbilical margin of the 

 last segment, often irregular both as to form and 

 position ; sometimes with a second slitlike aperture 

 at the peripheral angle of the segments, chiefly found 

 in the group of the P. elegans type (Ej^iistomma). Face 

 of the terminal segment sometimes inflated and 

 studded with larger perforations. Some species 

 pelagic. CarhoniferouH to Becent. 



Example. — P. Memtrdii, D'Orbigny sp. (Butalid), 

 'Ann. Sci. Nat.' vol. vii. 1820, p. 273, No. 2G ; 

 ' Modele,' No. 10. 



This is an abundant species in certain pelagic 



