FORAMINIFERA OF THE ATLANTIC OCEAN 



121 



Test nearly plano-convex, dorsal side nearly flat, ventral side 

 convex, peripheiy subcaiinate to rounded; chambers distinct, seven to 

 nine in the adult whorl, the inner end on the dorsal side with a definite 

 proximal portion, fusing wdth adjacent ones to form a concentric 

 band about the middle, and more or less separated by a series of 

 depressions; sutures deep on the ventral side, slightly limbate and 

 flush on the dorsal side; wall smooth, finely perforate; aperture 

 largely dorsal, with a thin lip; color usually deep yellowish-brown. 



Diameter up to 0.80 mm. 



This species described from the Miocene, Choctawhatchee marl of 

 Florida, is common living off the coast of Florida and adjacent 

 waters in comparatively shallow depths. The early stages are some- 

 what similar to Cibicides americana (Cushman), but adults normally 

 show the peculiar projections of the chambers. It is probable that 

 the form figured by H. B. Brady, Parker and Jones from the Abrohlos 

 Bank off Brazil belongs here.'*^ 



Cibicides concentrica — Material examined 



CIBICIDES ROBERTSONIANA (H. B. Brady) 



Plate 23, figures 6 a-c 



Truncatulina robertsoniana H. B. Brady, Quart. Journ. Micr. Sci., vol. 21, 

 1881, p. 65; Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 664, pi. 95, 

 figs. 4 a-c. — Egger, Abhandl. kon. bay. Akad. Wiss. Miinchen, CI. II, 

 vol. 18, 1893, p. 402, pi. 16, figs. 34-36.— Woodward, The Observer, vol. 

 4, 1893, p. 177.— Chapman, Proc. Zool. Soc. London, 1895, p. 40. — Flint, 

 Ann. Rep't. U. S. Nat. Mus., 1897 (1899), p. 333, pi. 77, fig. 3.— Heron- 

 Allen and Earland, Journ. Roy. Micr. Soc, 1909, p. 681. — Pearcet, 

 Trans. Roy. Soc. Edinburgh, vol. 49, 1914, p. 1028. — Heron-Allen and 



" Trans. Zool. Soc, liondon, vol. 12, 1883, pi. 46, figs. 7 a-c. 



