Conradia clathrata A. Adams, 1860: 410 [Type locality: Straits of Korea, 63 fms]. Type material. Conradia clathrata Adams, 1860, 2 syntypes (NHMUK 1878.1.28.436). Locality: Straits of Korea. H. Adams collection. (The 2 syntypes are glued to a board with 4 other specimens from the Hugh Cuming collection; it is impossible to distinguish them). Examined from photographs.

Description. Based on the syntype (NHMUK 1878.1.28.436): Shell very small (<3.0 mm in diameter), robust, high spired, turbiniform, formed by 4,75 whorls, carinated and narrowly umbilicate. Smooth protoconch with almost 3/4 whorls. The teleoconch has 4 whorls and its periphery is carinated. Ornamentation formed by spiral cords (carinae), axial ribs and variciform thickenings. Cords and ribs of similar size at first whorls, form a regular reticle of rectangular spaces; the axial ribs cross the spiral cords but without forming nodules at the crossing points. At last whorl there is a predominance of spiral sculpture; the spiral cords (carinae) protrude over the axial ribs, angulating the rounded periphery of the teleoconch. In apertural view, 2 spiral cords can be seen in the first three whorls and 5 in the last (1 subsutural, 2 peripheral, 1 basal and 1 periumbilical); in addition to several variciform thickenings. The subsutural cord forms a sloping shoulder, which is characteristic and extends between the suture and the subsutural cord and on which the axial ribs are distributed.The periumbilical cord is thicker than other cords, it delimits the umbilicus and above it; the cords cross the axial ribs.The umbilicus is narrow and deep, and it is placed between the periumbilical cord and the columellar lip. Aperture rounded, prosocline; columella thick, slightly arched, widened at the base with an anterior channel. Edge of the outer lip modified by the spiral cords, with the internal margin scalloped and the externalmargin thickened or variciform. Dimensions: The syntype measures 2.80 mm in diameter.

Conradia clathrata is characterized by the predominance of spiral sculpture; for its thick axial ribs; for the presence of variciform thickening on the last whorl and on the outer lip.
Conradia cingulifera, type species of the genus, is differentiated by the greater number of spiral cords and by the shape of the periumbilical cord. The specimen of Conradia clathrata A. Adams, 1860 figured in Okutani (2000) as well as those illustrated by Sasaki (2006) and Hickman (2013) as Conradia sp. cf. clathrata A. Adams, 1860 does not correspond to the photographed syntype, being in our opinion a different species.

Habitat. At 113 m deep (A. Adams, 1860); in sand bottom, 50-160 m (Higo, Callomon & Goto, 1999) and in sand bottom at 70-100 m deep (Okutani, 2000).
Distribution. Straits of Korea (A. Adams, 1860); Japan Sea: Mishima, Wakasa Bay and Toyama Bay (Higo, Callomon & Goto, 1999); Toyama Bay and western Japan Sea (Okutani, 2000).