62 BULLETIN 161, UNITED STATES NATIONAL MUSEUM 



Nairai, Fiji; 18 fathoms, Vavau Anchorage, Tonga Islands; and 

 7 fathoms, Rotonga. 



Genus SPIROLINA Lamarck, 1804 



Spirolina Lamarck, Ann. Mus., vol. 5, p. 244, 1804. 

 Synonym: Peneroplis (part) of authors. 



Genotype. — By designation, Spirolina cylindracea Lamarck. 



Test similar to Peneroplis, thick, early chambers close coiled, usu- 

 ally not completely involute, later ones uncoiled; aperture rounded, 

 terminal. Cretaceous (?) to Recent. 



SPIROLINA ARIETINA (Batsch) 



Plate 19, Figures 4, 5 



Nautilus (Lituus) arietinus Batsch (in part). Conch. Seesandes, p. 4, pi. 6, fig. 

 15c, 1791. 



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

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

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

 Soc. ZooL, vol. 28, pp. 179, 207 (list), 1901, p. 400 (list), 1902.— Heron-Allen 

 and Earland, Trans. Zool. Soc. London, vol. 20, p. 602, 1915. — Cushman, 13th 

 Ann. Rep. Florida Geol. Survey, p. 62, 1921; U. S. Nat. Mus. Bull. 100, 

 vol. 4, p. 482, 1921; Proc. U. S. Nat. Mus., vol. 59, p. 75, pi. 18, fig. 10, 1921.— 

 Heron-Allen and Earland, Bull. Soc. Sci. Hist. Nat. Corse, 1922, p. 125. — 

 Cushman, Carnegie Inst. Washington Publ. 311, p. 79, 1922. — Heron-Allen 

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



Peneroplis pertusus var. arietinus Woodward, The Observer, vol. 4, p. 77, 1893. — 

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

 Rep. 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, p. 7, 1910.— Cushman, U. S. Nat. Mus. BuU. 

 71, pt. 6, p. 88, pi. 36, fig. 2; pi. 37, fig. 5, 1917; Carnegie Inst. Washington 

 Publ. 213, p. 290, 1918. 



Spirolina arietina Cushman, U. S. Nat. Mus. Bull. 104, pt. 7, p. 43, pi. 15, figs. 

 4, 5, 1930. 



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; 

 wall longitudinally striate; aperture consisting of a series of inde- 

 pendent pores in the central portion of the apertural face. 



This is a common species in the Mediterranean and Indo-Pacific, 

 and I have seen it rare in the West Indian region. The early stages 

 are very similar to forms which have been often referred to Peneroplis 

 pertusus (Forsk&,l). Specimens showing the uncoiling well developed 

 are not common in our material, but a few occur to connect the young 

 coiled stages with the adult. All the specimens but one are from 



