THE FAMILY TEXTULAEIID^ 171 



Genus Valvulina, D'Oebigny. 



Test not dimorphous, spiral, typically triserial, 

 with three segments or rarely more in each convolu- 

 tion ; free or adherent ; aperture j)artially covered by 

 a valvular lip. Carhoniferous to JRecent. 



Example. — F. palceotrocJms, Ehrenberg sp. (Tetra- 

 taxis and Textilaria), ' Mikrogeologie,' 1854, pi. xxxvii. 

 par. xi. figs. A\ 1-4. 



The valvular aperture pertaining to the genus is 

 well seen in the above species. In contour it 

 resembles V. conica, but the test is largely calcareous, 

 and the chambers more numerous and compressed. 

 Carhoniferous. 



DiMOEPHOUs (Valvuline) Foem. 



Genus ClavuUna, D'Oebigny. 



Early segments triserial (valvuhne), later ones 

 uniserial and rectilinear ; test generally either cylin- 

 drical or trifacial ; aperture valvular. Eocene to 

 Recent. 



Example. — C. communis, D'Orbigny, 'Ann. Sci. 

 Nat.' vol. vii. 18i^6, p. 268, No. 4. 



This species is well distributed through the princi- 

 pal Tertiary strata. It is found in fairly deep water 

 at the present day. Goes records it as occurring 

 from 700 to 1,400 fathoms in the Pacific, and from 

 •20 to 1,800 fathoms in the Caribbean Sea. Eocene 

 to Recent. (Plate 9, figs. M, m.) 



