FORAMINIFERA OF THE ATLANTIC OCEAN 25 



ELPHIDIUM ADVENUM (Cushman) 



Plate 10, figures 1-2 



Polystomella subnodosa H. B. Brady (not von Miinster), Rep. Voy. Chal- 

 lenger, Zoology, vol. 9, 1884, p. 734, pi. 110, figs. 1 a, b. — Chapman, Journ. 

 Linn. Soc. Zool., vol. 28, 1902, p. 203. — Millett, Journ. Roy. Micr. 

 Soc, 1904, p. 604.— Bagq, Proc, U. S. Nat. Mus., vol. 34, 1908, p. 165.— 

 Heron-Allen and Earland, Trans. Zool. Soc. London, vol. 20, 1915, 

 p. 733. 



Polystomella advena Cushman, Publ. 311, Carnegie Instit. Washington, 

 1922, p. 56, pi. 9, figs. 11, 12; Publ. 342, 1924, p. 48; Publ. 344, 1926, p. 80, 



Test of medium size for the genus, strongly compressed, periphery 

 acute, with a narrow carina, somewhat lobulate, sides nearly parallel 

 in peripheral view, umbilical regions depressed, often with a small 

 central boss of clear shell material but in peripheral view not projecting 

 beyond the contour of the test; chambers distinct, 10 to 15 in the last- 

 formed coil, slightly inflated, especially in the last-formed portion; 

 sutures depressed, marked by the retral processes which are short, 

 about one-fourth the width of the chamber, 12 to 15 in number; wall 

 smooth, translucent, finely and distinctly perforate; aperture composed 

 of a series of small rounded pores at the base of the apertural face. 



Diameter, up to 0.50 mm.; thickness, 0.15 mm. 



The types of this species are from the Tortugas region off southern 

 Florida. The species is well distributed in warm, shallow water of 

 tropical regions. It is very different from von Miinster's species 

 from the Oligocene of northern Germany. It is not as common 

 in the West Indian region as are several of the other species. 



It apparently occurs in the Late Tertiary of the West Indian region. 



ELPHIDIUM ADVENUM (Cushman), var. MARGARITACEUM, new variety 



Plate 10, figure 3 



Variety differing from the typical mainly in the character of the 

 wall which in the variety is pearly and coarsely perforate, giving a 

 very distinctive appearance to the test. 



Holotype (Cushman Coll. No. 10227), from beach at Newport, 

 R. I. It appears to be a northern variety of the more tropical 

 E. advenum and somewhat similar specimens appear off the coasts of 

 Europe. 



ELPmDIUM POEYANUM (d'Orbigny) 



Plate 10, figures 4-5 



Polystomella poeyana d'Orbigny, in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 

 1839, "Foraminiferes", p. 55, pi. 6, figs. 25, 26.— Cushman, Publ. 311, 

 Carnegie Instit. Washington, 1922, p. 55, pi. 9, figs. 9, 10; Publ. 344, 1926, 

 p. 79. 



Test of small size for the genus, strongly compressed, periphery 

 broadly rounded, margin slightly lobulate, sides nearly parallel in 

 peripheral view, umbilical regions slightly depressed; chambers aver- 

 aging 10 to 12 in number in the last-formed coil but variable, very 



