FORAMINIFEKA OF THE ATLANTIC OCEAN 



43 



Length of western Atlantic specimens not over 0.50 mm. 



This form has usually been referred to Lamarck's "P. cylindracea" 

 based on Eocene specimens from France. An examination of the 

 French specimens shows that Lamarck's species is thicker and heavier, 

 and the wall has distinct, sharply raised costae, altogether different 

 from the species that occurs in the present ocean, at least in the 

 western Atlantic. These specimens which are very rare from Jamaica 

 and the Tortugas are referred to Batsch's recent species, the types of 

 which are from the Mediterranean. 



A comparison of other recent material referred to Lamarck's 

 species should be made with Eocene material from the type locality. 



Spirolina acicularis — Material examined 



SPIKOLINA ARIETINUS (Batsch) 



Plate 15, figures 4, 5 



Nautilus {Liiuus) arietinus Batsch (part), Conch. Seesandes, 1791, p. 4, 

 pi. 6, fig. 15c. 



Peneroplis arietinus Parker, Jones, and H. B. Brady, Ann, Mag. Nat. 

 Hist., ser. 3, vol. 16, 1865, p. 26, pi. 1, fig. 18.— H. B. Brady, Rep. Voy. 

 Challenger, Zoology, vol. 9, 1884, p. 204, pi. 13, figs. 18, 19, 22.— Chapman, 

 Journ. Linn. Soc. Zool., vol. 28, 1900, pp. 149, 207, (list), 400 (list).— 

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

 p. 602. — CusHMAN, 13th Ann. Rep't Florida Geol. Survey, 1921, p. 62; 

 BuU. 100, U. S. Nat. Mus., vol. 4, 1921, p. 482; Proc. U. S. Nat. Mus., 

 vol. 59, 1921, p. 75, pi. 18, fig. IO.-^Heron-Allen and Earland, Bull. 

 Soc. Sci. Hist. Nat. Corse, 1922, p. 125. — Cushman, Publ. 311, Carnegie 

 Instit. Washington, 1922, p. 79. — Heron-Allen and Earland, Trans. 

 Zool. Soc. London, vol. 22, 1926, p. 69 (list). 



Peneroplis perlusus, var. arietinus Woodward, The Observer, vol. 4, 1893, 

 p. 77. — A. SiLVESTRi, Atti Accad. Sci. Acireale, vol. 7, 1895-96, p. 42. — 

 Dakin, Rep't Pearl Oyster Fish. Ceylon, 1906, p. 231. — Heron-Allen 

 and Earland, Journ. Roy Micr. Soc, 1909, p. 319. — Sidebottom, Mem. 

 Proc. Manchester Lit. Philos. Soc, vol. 54, No. 16, 1910, p. 7. — Cushman, 

 BuU. 71, U. S. Nat. Mus., pt. 6, 1917, p. 88, pi. 36, fig. 2; pi. 37, fig. 5; 

 Publ. 213, Carnegie Instit. Washington, 1918, p. 290. 



Test in the early portion close coiled but not completely involute, 

 somewhat compressed, later portion uncoiling and the chambers 

 broadly elliptical in transverse section; chambers distinct, the later 

 ones slightly inflated; sutures distinct, earlier ones often slightly 

 raised, somewhat limbate, later ones narrow and slightly depressed; 

 62996—30 4 



