Length, 24 mm; diameter, 9 mm.

Shell: fusiform; anterior end truncate; with closely spaced, strong, narrow spiral cords; chestnut brown with darker spirals. Spire: one and one-half times the length of the aperture plus canal; protoconch of four and one-half whorls, brown, densely sculptured with slightly curved, strong, rounded axials crossed by weaker spiral threads; teleoconch of ten lightly convex whorls. Sculpture: subsutural fold slightly raised with three spiral threads; sinus rib with three threads; two primary cords and finer threads between sinus rib and lower suture; last whorl and fasciole with cords and threads; interspaces of cords obliquely striated, Aperture: sinus deep and narrow. Color: chestnut-brown, the primary cords darker and with traces of brown maculations on the whorls; parietal callus, columella and intertor of aperture white.

Powell (1964) notes that it is a member of the cingulifera series of species which ranges from the Indian Ocean to southern Japan, New Caledonia, Fiji, and the Marshall Islands.

X. castanella was described from the Hawaiian Islands. This is a rather rare species occurring at depths of 16 to 40 m.