DIAGNOSIS.—A small, elongate-pyramidal species, from 2 to 5 mm in length, glassy when fresh, whitish when long dead, the lower part of the whorls angulate, where low, broad axial ribs are crossed by 2 spiral cords that are nodose on the ribs, the nodes white in fresh specimens; 2 or 3 more or less strong varices are present.
DESCRIPTION.—Shell small, generally about 2 to 2.25 mm in length but reaching almost 5 mm, glassy, white when long dead, narrowly elongate-pyramidal; protoconch broadly mammillate-conical, of about smooth, rounded whorls; postnuclear whorls 8+, first 3 with 2 or 3 fine spiral lirae on lower half of whorls, the last 5 whorls angulate at the periphery, the uppermost spiral lira prominent and angulately nodose on the broad, low axial ribs that begin appearing on about the fourth postnuclear whorl; the nodes white in fresh, glassy specimens; the next lower spiral lira is somewhat less prominent, and also nodulose, and the lowest lira is a fine suprasutural cord; several stout, often whitish varices are present on the last 3 whorls. Aperture ovate, outer lip broken in specimens available, but probably thin and rounded; junction of parietal and columellar lip somewhat angulate, latter with a weak flexure and somewhat angulate and slighlty effuse at the juncture with the basal portion of the outer lip; an adult though worn specimen shows what looks like a narrow, rather vertical siphonal fasciole separated from the columellar lip by a weak, narrow fissure. Both Easter Island specimens of this species that I have seen are dead and partially broken or rather worn, as well as considerably larger than the Hawaiian shells. However, the sculpture, shape of the whorls, nature of the peristome, and presence of varices, leads me to assign them to this Hawaiian species, which has long been in our collection bearing one of Dall’s manuscript names. This species is one of many species described by Dall in his manuscript of Hawaiian marine mollusks that was unfortunately never published. Additional and fresh material from Easter Island may show that specimens from there represent a large race distinct from the Hawaiian material.
ETYMOLOGY.—From the Greek aktinos (ray, beam); Dall's reason for choosing this name is not clear.

RANGE.—Hawaiian Islands and Easter Island.
Holotype, Hawaii: Width: 0.95 mm; Height 2.15 mm. MATERIAL.—Holotype: in 33-50 fathoms (59.4-90.0 m), off Waikiki, Oahu, Hawaii, D. Thaanum, USNM 339456.