FORAMINIFERA OF THE ATLANTIC OCEAN 41 



GYROIDINA SOLDANn d'Orbigny, var. ALTIFORMIS R. E. and K. C. Stewart 



Plate 8, figures 10 a-c; plate 9, figures 1 a-c 



Gyroidina soldanii d'Orbigny, var. altiformis R. E. and K. C. Stewart, 

 Journ. Pal., vol. 4, 1930, p. 67, pi. 9, figs. 2 a-c. 



Variety differing from the typical in the deep form of the test and 

 the chambers of the last-formed whorl which have the faces flattened 

 obliquely and tilted giving a peculiar overlapping appearance to 

 chambers, the dorsal sutures are also somewhat raised. 



This variety has been recently described from the Pliocene of 

 California, and appears to be living in restricted areas in the Western 

 Atlantic. Plate 8, figure 10 shows a fairly young specimen, and 

 Plate 9, figure 1 an adult. 



Gyroidina soldanii, var. altiformis — Material examined 



Genus ROTALIATINA Cushman, 1925 



Rotaliatina Cushman, Contr. Cushman Lab. Foram. Res., vol. 1, 1925, p. 4; 



Special Publ. No. 1, Cushman Lab. Foram. Res., 1928, p. 272. 

 Rotalina (part) of Authors (not d'Orbigny). 



Genoholotype. — Rotaliatina mexicana Cushman. 



Test free, trochoid, close coiled, composed of about three volutions, 

 the last one composed of numerous chambers, all visible from the 

 dorsal side, only those of the last-formed coil from the ventral side, 

 ventrally umbilicate; wtJI calcareous, finely perforate; aperture, an 

 arched slit between the base of the apertural face and the previous 

 coil. 



Eocene. 



Subfamily 4. ROTALIINAE 



Test trochoid, umbilical region typically closed, sometimes with a 

 definite conical plug of clear shell material; wall of the test often 

 double and a tubular canal system developed; aperture ventral, along 

 the margin of the chamber between the periphery and the umbilical 

 area. 



