AET. 25 POBAMINIFERA — CUSHMAN AND KELLETT 9 



Genus REUSSIA Schwager, 1877 



REUSSIA SPINULOSA (Reuss) 



Plate 3, figures 10 a, b 



Verneuilina spinulosa Reuss, Denkschr. Akad. Wiss. Wien, vol. 1, 1850, p. 374, 



pi. 47, fig. 12. — (and later Authors). 

 Reussia spinulosa Schwager, Boll. Com. Geol. Ital., vol. 8, 1877, p. 26, pi., fig. 66. 



There is a single specimen of Reussia from off Santa Elena, Ecuador 

 which may be refered to this species. The apertural end is incomplete. 



Family ROTALIIDAE 

 Genus DISCORBIS Lamarck, 1804 



DISCORBIS ISABELLEANA (d'Orbigny) 



Plate 3, figures 12 a-c 



Rosalina isabelleana d'Orbigny, Voy. Am^r. Merid., 1839, vol. 5, pt. 5, " Foram- 



inifSres," p. 43, pi. 61, figs. 10-12. 

 Discorbina isabelleana H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, 



p. 646, pi. 88, figs. 1 a-c (?). 

 Discorbis isabelleana Cushman, Bull. Scripps Instit. Oceanography, Tech. Ser., 



vol. 1, 1927, p. 160, pi. 4, fig. 4. 

 Discorbina vilardeboana H. B. Brady (not d'Orbigny), Rep. Voy. Challenger, 



Zoology, vol. 9, 1884, p. 645, pi. 88, fig. 2. 



Test trochoid, in edge view biconvex, spire low; periphery acute 

 but not carinate; six chambers in the last-formed coil, distinct, 

 increasing regularly in size as added, ventrally with a slight lip in the 

 umbilical region which is depressed; sutures very distinct, strongly 

 curved; wall smooth, finely perforate; aperture, a narrow ventral slit 

 below the umbilical border of the chamber. 



Length, 0.25 mm.; breadth, 0.18 mm.; thickness, 0.10 mm. 



This species is widely distributed along the Western Coast of the 

 Americas. It is recorded under the name of Discorhina vilardeboana 

 by various authors basing the determination on the Challenger figures 

 rather than that of d'Orbigny which do not belong to the same species. 

 Our specimens are from Lota, Chile, and Pimentel, Peru. 



DISCORBIS CHILIENSIS, new species 



Plate 3, figures 11 a-c 



Test plano-convex, dorsal side strongly convex, ventral side flat- 

 tened or concave, periphery acute but not carinate, somewhat involute 

 on the dorsal side; chambers distinct, about seven in the last-formed 

 whorl, sHghtly inflated on the ventral side and ending in a distinct 

 angle at the umbilical end; sutures distinct, on the dorsal side slightly 

 limbate and raised, strongly curved, on the ventral side depressed, 

 gently curved ; wall rather coarsely perforate ; aperture on the ventral 

 side below the umbilical margin of the chamber. 



