FORAMINIFERA OF THE ATLANTIC OCEAN 



123 



between the last few chambers, on the ventral side gently curved, 

 somewhat limbate in the early stages, usually not so later, but some- 

 what depressed; wall on the dorsal side especially, very coarsely 

 perforate, the sutures sometimes extending above the test on the 

 dorsal side but usually to a very slight amount; aperture peripheral 

 and extending along the inner margin of the chamber on the dorsal 

 side, often with a thin lip. 



This species was described originally from the Miocene, Choctaw- 

 hatchee marl of Florida. Similar specimens are common living off 

 the coast of Florida and in adjacent regions as figured here (pi. 23, 

 figs. 3 to 5). A study of a large series of Atlantic specimens of 

 forms that were assigned by Brady to " Truncatulina akneriana" and 

 " T. ungeriana" in the Challenger Report together with topotype 

 material of these d'Orbignyan species leaves a very peculiar situation. 

 Such specimens as those figured by Brady do not at all fit the characters 

 of d'Orbignj^'s species from the Vienna Basin Miocene from which 

 area I have abundant specimens for studJ^ A part of these forms maj 

 be included under the following species. 



Cibicides floridana — Material examined 



CIBICIDES PSEUDOUNGERIANA (Cushman) 



Plate 22, figures 3-7 



Truncatulina ungeriana H. B. Brady (not Rotalina ungeriana d'Orbigny 1826 

 and 1846), Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 664, pi. 94, 

 figs. 9o-c. 



Truncatulina pseudoungeriana Cushman, U. S. Geol. Surv., Prof. Paper 

 129-E, 1922, p. 97, pi. 20, fig. 9; 129-F, 1922, p. 136; 133, 1923, p. 40. 



Test biconvex to plano-convex, periphery subacute to somewhat 

 bluntly rounded; chambers generally nine to eleven in the adult whorl 

 but the number very different in the megalospheric and microspheric 

 forms; sutures distinct and usually limbate, often strongly so and 



