DIAGNOSIS.—Shell small, white, broadly oval, rather elevated, apex posteriorly directed and about 1/4 of total length from posterior margin, strongly cancellated by axial ribs and concentric lirae. Somewhat smaller, more elevated, and with finer cancella-tion than E. subclathrata Pilsbry, 1890, from the central Pacific.
DESCRIPTION.—Shell rather small, 2.7 to 6 mm in length, broadly oval, moderately elevated with apex involute, directed posteriorly and situated at about ¼ of the total length from the posterior margin (in larger specimens occasionally more anteriorly located, in smaller ones closer to the posterior edge). Exterior white, sculptured with 21 to 24 rather strong axial ribs and numerous, somewhat more slender concentric ridges, which near the apex and often at the sides of the upper half of the selenizone are fine and crowded but on the rest of the shell are stronger and more distant, forming nodes where they intersect the axial ribs and resulting in a pattern of deep squarish pits. The selenizone is elevated between two narrow ribs and sculptured with a series of rather crowded, curved, or roundish nodes; the sinus is narrow and moderately deep, measuring about 1/5 of the total length of the shell.
length 4.91 width 3.5 height 1.83

This species is closest to Emarginula subclathrata Pilsbry, 1890. Pilsbry proposed this taxon for the figure that Sowerby in 1866 had given for E. clathrata Pease, 1863, as he felt that the Sowerby figure depicted a shell different, shorter, and broader than what might properly be included in E. clathrata Pease. Kay, however, examined Sowerby's specimen (Kay 1965:75) and found that it falls well within the ränge of variability of the Pease species. Since Pease's name is preoccupied by Emarginula clathrata Deshayes, 1824, and E. clathrata Adams and Reeve, 1850, Pilsbry's name can be used for Pease s species, and the name E. peasei Thiele, 1915 is unnecessary.
I have been able to examine the specimen desig-nated as holotype of Emarginula concinna A. Adams, 1852, to which Couturier referred his material from the Tuamotus (Couturier, 1907:172). This specimen agrees with the figure given by Adams and Sowerby (1863:212, pl. 246: figs. 34, 39, 40), and has 25 radiating ribs, not 12 as mentioned in the original description account, which may represent the number on one side only. Pilsbry (1890-1891:257) is probably correct in stating that Emarginula concinna A. Adams may be a synonym of E. elongata Costa, 1829 (not of E. cancellata Philippi, 1836). I have compared the holotype with specimens of E. elongata from the Mediterranean and can find no essential diflferences.
Emarginula elongata Costa is larger, more elevated, with more numerous radiating ribs, 28-33 in number, than this new species.

Easter Island, Tuamotus, and Gambier Islands.