Iotyrris cerithiformis: Adult shell 33 to 53 mm. (1,25 to 2 inches) in height, whorls 10 or 11, plus a multi-spiral narrowly conic protoconch of 4 to 4,5 whorls, brown, densely sculptured with slightly curved strong rounded axials crossed at right angles by weak spiral lirae. Spire tall, almost twice the height of the aperture plus canal, 24° to 27°, outlines lightly convex except for bulging subsutural fold and sinus rib. Sculpture of spire whorls consisting of a broadly convex subsutural fold bearing 3 to 5 weak spiral threads, separated by a narrow deeply channeled concavity from the sinus rib, situated at about middle whorl height and composed of two moderately strong, rounded, spiral cords with a concavity between. Below the sinus area there are 2 to 4 crisp cords of varying strength. About 10 primary cords and occasional interstitial threads on the base from below the sinus area plus 4 cords on the weak fasciole. .Sinus deep and narrow. Colour white, rather evenly speckled with reddish brown dots and dashes; larger maculations not present.

Iotyrris cerithiformis: Shell: fusiform; anterior end truncate; sculpture of densely concentrated spiral cords and threads; white speckled with redbrown. Spire: twice the length of the aperture plus the canal; protoconch of four or four and one-half brown whorls densely sculptured with slightly curved axial ribs crossed by spiral lirae; teleoconch of ten to eleven slightly convex whorls. Sculpture: subsutural fold broadly convex with three to five weak spiral threads; sinus rib separated from subsutural fold by a deep concavity, with two strong threads; remainder of whorls with cords and threads of varying strength. Aperture; sinus deep and narrow; siphonal canal slightly recurved. Color: white evenly speckled with red-brown dots and dashes.

Iotyrris cerithiformis: Length, 29 mm; diameter, 8 mm.

Iotyrris cerithiformis: Powell (1964) distinguished the Hawaiian shells from these of Xenuroturris millepunctatus (Sowerby, 1908b) from New Caledonia, Fiji, Japan, and Okinawa by their more rounded whorls, less sharply angled base, and less deeply excavated neck.

Iotyrris cerithiformis: This species was described from the Hawaiian Islands. Shells are fairly common at depths of from 10 to 80 m.

Iotyrris cerithiformis: XENUROTURRIS CERITIFORMIS. Powell, 1964:324, pl. 175, figs. 14, 15, pl. 252. 8–10 fm, entrance to Honolulu Harbor, Oahu Island, Hawaii. Powell, 1966; Powell, 1967:442(22–964a), pl. 175, figs. 14, 15, pl. 252; Rehder & Ladd, 1973; Kay, 1979:341, fig. 113M; McDowall, 1984.
OTHER COMBINATIONS: Turris cerithiformis Tinker, 1952:46, pl. 47, upper row; Iotyrris cerithiformis Sysoev, 2002:169, figs. 1H–K, 2A, B; Medinskaya, 2003a:125, fig. 4A; Medinskaya, 2003b.
SYSTEMATICS: Conspecific with Pleurotoma lirata Pease, 1869, non Pleurotoma lirata Reeve, 1845a, cerithiformis Powell, 1964.
ATTRIBUTIONS: Attributed to Tinker by Powell, 1964, however, Powell, 1967, said that Tinker’s use of Dall’s manuscript names did not validate the names and further said that this name should date from Powell, 1964.