76 BULLETIN 104, UNITED STATES NATIONAL MUSEUM 



Genus NEOCRIBRELLA Cushman, 1928 



Neocribrella Cushman, Contr. Cushman Lab. Foram. Res., vol. 4, 1928, p. 6; 



Special Publ. No. 1, Cushman Lab. Foram. Res., 1928, p. 280. 

 Discorbina (part) Parker and Jones, Philos. Trans., vol. 155, 1865, pp. 385, 



421. 

 Genoholotype. — Discorbina globigerinoides Parker and Jones. 



Test trochoid but becoming somewhat involute in the later stages; 

 chambers comparatively few, inflated; wall calcareous, perforate; 

 aperture in the adult composed of several small rounded pores in a 

 slight depression of the ventral face of the chamber. 



Eocene — France. 



There are no Recent species of this genus. 



Family 34. AMPHISTEGINIDAE 



Test trochoid, all chambers visible from the dorsal side except in 

 involute forms of Amphistegina, those of the last-formed whorl only 

 visible on the ventral side, the ventral side with angular supplementary 

 chambers coming in between the regular series, roughly rhomboid in 

 shape as seen from the surface; aperture typically ventral, a slightly 

 arched opening, the area adjacent to the aperture, papillate. 



This family consists of the two genera given below. The simpler 

 of these, Asterigerina, is known from the Upper Cretaceous and 

 Tertiary, and is living in the present oceans. Amphistegina, the more 

 complex genus of the two, also is known from about the same geologic 

 range. The Paleozoic records of this genus are undoubtedly errone- 

 ous. Both genera are most abundant in fairly shallow water under 

 coral reef conditions in the tropics. The family evidently developed 

 from the Rotaliidae. 



Genus ASTERIGERINA d'Orbigny, 1839 



Asterigerina d'Orbigny, Voy. Amer. Merid., vol. 5, pt. 5, 1839, "Foramini- 

 feres", p. 55. — Cushman, Special Publ. No. 1, Cushman Lab. Foram. 

 Res., 1928, p. 281. 



Genotype, by designation. — Asterigerina carinata d'Orbigny. 



Test trochoid, biconvex, the ventral side usually more strongly so 

 than the dorsal, dorsal side with the chambers appearing regularly 

 coiled, on the ventral side with angular supplementary chambers 

 coming in between the regular series, large and regularly rhomboid 

 in shape; sutures on the dorsal side a simple curve; aperture on the 

 ventral side at the base of the chamber margin. 



Eocene to Recent. 



The earliest record for the genus is "Asterigerina lobata d'Orbigny" 

 recorded by Reuss from the Cretaceous of Germany. There are fossil 

 species recorded from the Eocene, Oligocene, Miocene, and Pliocene. 

 The Recent species is known from the general West Indian region and 

 the east coast of South America. There are records from the Atlantic 

 coast of Europe, but from the figures it seems very doubtful if they 

 are truly Asterigerina. 



