GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 73 



usually filled with secondary shell material and a slight extension 

 peripherally along the sutures which are slightly depressed; aper- 

 ture a narrow curved slit. 



Diameter 0.60 mm. Cat, Nos. 324680-1, U.S.N.M. 



Distribution. — Specimens of this species occurred in the Gatun 

 formation at U.S.G.S. No. 6033<?, in marl from second bed from 

 bottom, just below lower clay, Gatun Section, relocated line of the 

 Panama Railroad; and 6035, in gray green, fine grained, sandy shell 

 marl, vicinity of Mindi Hill. The specimens are rather typical, per- 

 haps varying in the direction of increased length from most recent 

 specimens. 



NONIONINA SCAPHA (Fitchel and Moll). 



Plate 25, figs. 6a, b. 



Nautilus scapha Fichtel and Moll, Test. Micr., 1803, p. 105, pi. 19, figs. d-f. 



Nonionina scapha Parker and Jones, Ann. Mag. Nat. Hist., ser. 3, vol. 5, 

 I860, p. 102, No. 4.— H. B. Brady, Nat. Hist. Trans. Northumberland 

 and Durham, vol. 1, 1865, p. 106, pi. 12, figs. 10a, &.— H. B. Brady, Rep. 

 Voy. Challenger, Zoology, vol. 9, 1884, p. 730, pi. 109, figs. 14, 15, and 

 16. — H. B. Brady, Parker, and Jones, Trans. Zool. Hoc, vol. 12, 1888, p. 

 230, pi. 43, fig. 20.— Woodward and Thomas, Geol. Nat. Hist. Surv. 

 Minnesota, vol. 3, 1893, p. 48, pi. B, figs. 35, 36.— Egger, Abh. kon. Bay. 

 Akad. Wiss. Miinchen, CI. II, vol. 18, 1893, p. 424, pi. 19, figs. 43, 44.— 

 Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 25, 1894, p. 104, pi. 17, 

 fig. 830.— Morton, Proc. Portland Soc. Nat. Hist., vol. 2, 1897, p. 121, 

 pi. 1, fig. 23.— Flint, Ann. Rep. U. S. Nat. Mus., 1897 (1899), p. 337, 

 pi. 80, fig. 1. — Fornasini, Mem. Accad. Sci. 1st. Bologna, ser. 6, vol. 1, 

 1904, p. 12, pi. 3, fig. 4; pi. 13, fig. 5.— Millett, Journ. Roy. Micr. Soc., 

 1904, p. 601.— Bagg. Proc. U. S. Nat. Mus.. vol. 34, 1908, p. 164.— Side- 

 bottom, Mem. and Proc. Manchester Lit. and Philos. Soc, vol. 53, No. 

 21, 1909, p. 13 ; vol. 54, No. 16, 1910, p. 29, pi. 3, fig. 13.— Bagg, Bull. 

 U. S. Geol. Surv. No. 513, 1912, p. 88, pi. 27, figs. 1-8. 



Polystomella crispa, var. (Nonionina) scapha Parker and Jones, Philos. 

 Trans., vol. 155, 1865. p. 404, pi. 14, figs. 37, 38 ; pi. 17, figs. 55, 56. 



Description. — Test in side view longer than wide, about ten cham- 

 bers in the last formed coil, rapidly increasing in length as added, 

 sutures evenly curved, slightly depressed, periphery broadly rounded, 

 in apertural view the face of the last formed chamber making up a 

 large part of the visible surface, wall smooth, finely punctate, some- 

 what umbilicate ; aperture an arched slit at the base of the chamber. 



Length 0.60 mm. Cat. No. 324682, U.S.N.M. 



Specimens of this species were collected in the Gatun formation 

 at a single station, U.S.G.S. No. 6033c, in marl from second bed 

 from bottom, just below lower clay, Gatun section, relocated line of 

 the Panama Railroad. 



The specimen figured in apertural view was placed to show the 

 aperture rather than the full size of the apertural face which is really 



