TROPICAL PACIFIC FORAMINIFERA OF "ALBATROSS" 7 



finely perforate; aperture radiate, at the peripheral angle, with a 

 distinct enlarged slit on the ventral side. Length, up to 0.9 mm; 

 breadth, 0.75 mm; thickness, 0.45 mm. 



This specific name has been used by many authors, but a reference 

 to the various forms will show that many specimens have been re- 

 corded under this name that are quite different from the species as 

 defined and figured by d'Orbigny. Specimens are rare, but occur at 

 several Albatross stations in deeper water, as shown in Table 5. In 

 addition to the deep-water Albatross stations, there are three speci- 

 mens from Mokaujar Anchorage, Fiji, in comparatively shallow 

 water. 



Table 5. — Robulus gibbus — material examined 



ROBULUS CALCAR (Linnaeus) 



Plate 2, Figures 3a, b 



"Nautilus minimus non umbilicatus" Gualtieri, Index Test., pi. 19, fig. C, 

 1742. 



"Nautili (Lenticulae radiatae) " Soldani, Testaceographia, vol. 1, pt. 1, p. 54, 

 pi. 33, figs, aa, bb, 1789. 



Nautilus calcar Linnaeus, Syst. Nat., ed. 12, p. 1162, no. 272, 1767; (Gmelin's) 

 ed. 13, p. 3770, no. 2, 1788. 



Cristellaria calcar H. B. Brady (part), Rep. Voy. Challenger, Zoology, vol. 9, 

 p. 55, pi. 70, figs. 9-12 (not figs. 13-15), 1884.— H. B. Brady, Parker, and 

 Jones, Trans. Zool. Soc. London, vol. 12, p. 224, pi. 44, fig. 14, 1888.— 

 Flint, U. S. Nat. Mus. Rep. for 1897, p. 318, pi. 66, fig. 1 (part), 1899.— 

 CusHMAN, U. S. Nat. Mus. Bull. 71, pt. 3, p. 72, pi. 32, fig. 4, 1913,- 

 U. S. Nat. Mus. Bull. 104, pt. 4, p. 115, pi. 30, fig. 7; pi. 31, figs. 4, 5, 1923. 



Robulus calcar Galloway and Morrey, Bull. Am.er. Pal., vol. 15, p. 20, pi. 2, 

 fig. 10, 1929. — CusHMAN, Contr. Cushman Lab. Foram. Res., vol. 5, p. 84, 

 pi. 12, fig. 18, 1929. — Cushman and Jarvis, Journ. Pal., vol. 4, p. 358, 

 pi. 32, fig. 9, 1930. 



Test close coiled, strongly biconvex, periphery usually with a single 

 acicular spine extending from each chamber, the spines usually 



