FAMILY 33. ROTALIIDAE 271 



Genus LAMARCKINA Berthelin, 1881 

 Plate 39, figure 11; plate 41, figure 6 



Genoholotype, Pulvinulina erinacea Karrer 



Lamar ckina Berthelin, Comptes Rendus Assoc. Franc. (Reims, 1880) 



1881, p. 555. 

 Megalostomina Rzehak, Ann. k. k. Nat. Hofmuseums, vol. 10, 1895, p. 



228 (genoholotype, Mcfjalostomina fuchsi Rzehak). 

 Pulvinulina (part) of authors. 

 Rotalina (part) of authors. 

 Discorbina (part) of authors. 

 Valvulina (part) of authors. 



Test trochoid, evidently attached, dorsal side convex, ventral 

 side usually flattened or concave, dorsal side usually ornamented, 

 ventral side very smooth and highly polished ; chambers distinct 

 on the dorsal side, less so on the ventral, each often with an 

 umbilical projection; wall finely perforate, calcareous, ventral 

 side thickened; aperture at the umbilical end of the chamber, 

 often enlarged by resorption. 



Upper Cretaceous to Recent. 



See Cushman, The Genus LamarcJcina and its American 

 Species (Contr. Cushman Lab. Foram. Res., vol. 2, 1926, pp. 

 7-14, pi. 4). 



Genus VALVULINERIA Cushman, 1926 



Plate 39, figure 12; plate 41, figure 5 

 Genoholotype, Valvulineria californica Cushman 



Valvuiineria Cushman, Contr. Cushman Lab. Foram. Res., vol. 2, 1926, 



p. 59. 

 Rosalina (part) of authors. 



Test usually trochoid, close coiled, all chambers of the several 

 coils visible from the dorsal side, only those of the last-formed 

 coil from the ventral side, umbilicate ; chambers numerous ; wall 

 calcareous, finely perforate; aperture ventral, large, extending 

 from the umbilical end of the chamber nearly to the periphery 

 and covered by a thin, membrane-like plate which largely fills 

 the umbilical area, in the adult the aperture often extending 

 into the ventral or peripheral face of the chamber, sometimes 

 becoming tripartite. 



Cretaceous to Recent. 



