TROPICAL PACIFIC FORAMINIFERA OF "ALBATROSS" 61 



or commencing to uncoil ; chambers undivided ; wall calcareous, imper- 

 forate except in the proloculum and sometimes the following chamber; 

 aperture simple, at the base of the apertural face, or long and slitlike, 

 occasionally divided. Cretaceous (?) Tertiary and Recent. 



This is the oldest and most primitive genus of this group, and from 

 it by modifications the other genera have been derived. 



PENEROPUS PLANATUS (Fichtel and Moll) 



Plate 19, Figures 1-3 



Nautilus {Lituus) arietinus Batsch (iu part), Conch. Seesandes, p. 4, pi. 6, 

 figs. 15a, 6, 1791. 



Nautilus planatus var. /3, Fichtel and Moll, Test. Micr., p. 91, pi. 16, figs. 

 d, e, f, 1803. 



Peneroplis planatus Montfort, Conch. Syst., vol. 1, p. 258, 65« genre, 1808. 



Cristellaria planaia Lamarck, Tableau Encycl. Math., pi. 467, figs, la-c, 1816. 



Cristellaria dilatata Lamarck, Tableau Encycl. Meth., pi. 467, figs. 2o-c, 1816. 



Peneroplis planatus d'Orbigny, Ann. Sci. Nat., vol. 7, p. 285, no. 1, 1826; Modeles 

 no. 16, 1826. — Williamson, Rec. Foram. Great Britain, p. 45, pi. 3, figs. 

 84, 85, 1858. — Schlumberger, Feuille Jeunes Nat., vol. 12, pi. 1, fig. 13, 

 1881.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, p. 204, pi. 13, fig. 15, 

 1884. — Jones, Foram. Crag, pt. 2, p. 133, pi. 6, fig. 5, 1895.- — Heron-Allen 

 and Earland, Trans. Zool. Soc. London, vol. 20, p. 601, 1915. — Cushman, 

 U. S. Nat. Mus. Bull. 100, vol. 4, p. 481, 1921.— Heron-Allen and 

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

 U. S. Nat. Mus. Bull. 104, pt. 7, p. 39, pi. 14, figs. 6, 7, 1930; Contr. 

 Cushman Lab. Foram. Res., vol. 7, p. 71, pi. 9, figs. 17, 18, 1931. 



Peneroplis pertusus var. planatus A. Silvestri, Atti Accad. Sci. Acireale, vol. 7, 

 p. 42, 1895-96.— Dakin, Rep. Pearl Oyster Fish. Ceylon, 1906, p. 231.— 

 Bagg, Proc. U. S. Nat. Mus., vol. 34, p. 124, 1905.— Sidebottom, Mem. 

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

 U. S. Nat. Mus. BuU. 71, pt. 6, p. 87, pi. 37, fig. 3, 1917; Carnegie Inst. 

 Washington Publ. 213, p. 290, 1918. 



Test much compressed, the early portion coiled planispirally but 

 often partially evolute, later portion very much complanate and 

 spreading out, reaching back on both sides toward the earlier cham- 

 bers, but not entirely embracing; chambers distinct, very slightly 

 inflated, broad and low; sutures distinct, depressed, occasionally 

 somewhat iimbate; wall very distinctly striate, the striae numerous 

 and nearly parallel to the periphery; apertures along the median line 

 of the narrow apertural face. Length, 1.1 mm; breadth, 0.85 mm; 

 thickness, 0.12 mm. 



This is particularly a species of the Mediterranean and Indo- 

 Pacific, and is the only representative of the genus in the material 

 examined, most of the other forms appearing to be Peneroplis being 

 only young stages of Spirolina. 



The species is recorded in our material from off Fiji, 40-50 fathoms; 

 Mokaujar Anchorage, Fiji; 12 fathoms off Levuka, Fiji; 12 fathoms off 



