FORAMINIFERA OF THE GENUS EHRENBERGINA 

 AND ITS SPECIES' 



By Joseph A. Cushman 



Of Sharon, Massachiisetts 



In 1850 Reuss erected the genus Ehrenbergina and for its genotype 

 described the species E. serrata Reuss from the Miocene of x\ustria. 

 Ehrenbergina is a genus related to Cassidulina and other genera of 

 the calcareous group which have been included in the Textulariidae, 

 in its biserial arrangement of the chambers but is clearly distinct in 

 the peculiar plan of development. It is definitely known as far 

 back as the Upper Eocene of America by a single species. Chapman 

 has figured and described a form referred by him to Ehrenbergina 

 pujM, (d'Orbigny) from the Cretaceous of England, but it seems from 

 the figure given to have very little relation to true Ehrenbergina. 



It seems to be indicated that the genus may have been developed in 

 American waters in the Upper Eocene and then became widely dis- 

 tributed in the Miocene at least. Records are very scattered and 

 Reuss' species and one from Australia from the Miocene are the 

 only ones from that formation and none are known from the Plio- 

 cene. There are a few records from the Pleistocene, all from the Pa- 

 cific and Antarctic. As a recent genus it is well distributed in the 

 Indo-Pacific and the tropical western Atlantic but most abundant in 

 the Pacific. There are several distinct species in the present oceans 

 with very definite distributions. 



Genus EHRENBERGINA Reuss, 1850 



Ehrenbergina Reuss (type E. serrata Reuss), Denkschr. Akad. Wiss. Wien, vol. 1 

 1850, p. 377.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, 

 p. 433. — Chapman, The Foraminifera, 1902, p. 179. — Cushman, Bull. 71, 

 U. S. Nat. Mus., pt. 2, 1911, p. 101; Bull. 104, pt. 3, 1922, p. 133. 



Cassidulina (part) d'ORBiGNY, Foram. Amer. M(§rid., 1839, p. 57. 



Test free, composed of numerous chambers arranged biserially 

 about an elongate axis with a definite dorsal and ventral side, the 

 dorsal with the chambers meeting evenly and alternating, the surface 

 usually smooth, the ventral side usually with a central groove and the 



> This is the second of a contemplated series of revisions of the genera of Foraminifera by Dr. J. A. Cush- 

 man. The first appeared as No 2597, of the Proceedings of the United States National Museum, vol. 67 , 

 1926, art. 25, pp. 1-24, with pis. 1-6: "Foraminifera of the Genera Siphogenerina and Pavonina." 



NO. 2665.— Proceedings U. S. National Museum. Vol. 70. Art. 16 



22087—27 1 



