140 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.77 



each succeeding chamber farther removed from the base; sutures 

 but little depressed, distinct; wall of medium thickness, smooth; 

 aperture radiate. 



Maximum length 1.55 mm.; breadth 0.80 mm.; thickness 0.35 mm. 



Holotype.— iCiit. No. 20856, U.S.N.M.) From Albatross D4805, off 

 Japan. 



Sigmomorphina aliceae is twisted, as is S. torta, from which it is 

 quite distinct in its flat later chambers. In general appearance, it 

 resembles Sigmomorphina pearceyi, but the latter has inflated cham- 

 bers, and the test is not twisted as much as in the present species. 

 The specific name is given for Alice E. Cushman, who took much 

 care in preparing our manuscript and in checking our proofs. 



Distribution. — Known only from off the coast of Japan. 



Genus SIGMOIDELLA Cushman and Ozav.a, 1928 



SIGMOIDELLA ELEGANTISSIMA (Parker and Jones) 



Plate 39, figure 1 a-c 



Polymorphina elegantissima Parker and Jones, Phil. Trans., vol. 155, 1865, 

 Table X, p. 438. — H. B. Brady, Parker, and Jones, Trans. Linn. 

 See, vol. 27, 1870, p. 231, pi. 40, figs. 15 h, c (not a).— H. B. Brady, 

 Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 566, pi. 72, fig. 13 (not 

 figs. 12, 14, 15).— Flint, U. S. Nat. Mus. Rept., 1897, p. 319, pi. 67, 

 fig. 4. — Bagg, Maryland Geol. Surv. (Eocene), 1901, p. 247, pi. 63, 

 fig. 11; (Miocene), 1904, p. 476, pi. 133, fig. 3.— Cushman, Bull. 71, 

 U. S. Nat. Mus., pt. 3, 1913, p. 90, pi. 38, fig. 1; U. S. Nat. Mus., Bull. 

 100, vol. 4, 1921, p. 267, pi. 54, figs. 1, 2. — Nuttall, Quart. Journ. 

 Geol. Soc, vol. 84, 1928, p. 93, pi. 6, fig. 10. 



Sigmoidella elegantissima Cushman and Ozawa, Jap. Journ. Geol. & Geogr., 

 vol. 6, 1929, p. 76, pi. 16, figs. 10, 11. 



Test compressed, almost circular excepting the slightly acute, 

 apertural end, margins angular; chambers elongate, overlapping, 

 arranged in a clockwise sigmoid series, each succeeding chamber 

 becoming much larger and embracing those previously formed, but 

 in old age specimens, the last one or two chambers not extending 

 down to the base; sutures not depressed, but generally distinct; wall 

 smooth; aperture radiate. 



Maximum length 2 mm.; breadth 1.60 mm.; thickness 0.85 mm. 



This beautiful species is only mentioned by Parker and Jones in 

 1864 and is first figured and described by H. B. Brady, Parker, and« 

 Jones in 1870. The species is discussed in detail in our paper on the 

 Polymorphinidae found in Japan. 



Distribution. — It is one of the most abundant species in warm seas 

 of the Australian region extending into the Philippine region, where 

 it is abundant, but not as far north as Japan, where it is replaced by 

 Sigmoidella kagaensis Cushman and Ozawa. It occurs in the late 

 Tertiary of the Australian and East Indian region. It is also com- 



