Description. Shell small, reaching about 15 mm. (about 3/5 inch) in length, solid, minutely perforate or rimate, strongly axially ribbed and finely threaded with spiral ridges. Whorls 8½ to 9 slightly shouldered and moderately convex. Nuclear whorls smooth and then finely ribbed and with a little trace of spiral sculpture. General color a dull gray to faintly purplish, both axial ribs and minute spiral ridges whitish. Early three whorls forming an angle of 44°, later whorls nearly straight sided. Aperture subcircular, holostomatous and more or less evenly flaring and slightly projecting beyond the body whorl. Mid-parietal wall supporting a well.defined tooth, columellar tooth absent. Lip flaring, simple and not developed into a collar. Suture indented but not well-defined. Axial sculpture con. sisting of strong costae, about on the body whorl. Spiral sculpture consisting of 25 to 30 fine, blade-like ridges that are best developed on the forward side of the axial costae.
length width whorls
14 6 mm. 9 Holotype
14.5 5.9 9½ Paratype
15 6.5 9½ Paratype
12.5 5.9 8 Paratype
Types. Holotype, Museum of Comparative Zoölogy, no. 184623 from Lydia Point, Great Inagua Island, Bahama Islands. R. A. McLean and B. Shreve collectors, July 1938. Paratypes in the Museum of Comparative Zoology, United States National Museum and the Museo Poey from the same locality and from Calm Cove and Canfield Bay collected by McLean and Shreve and a large series from south of North East Point and east of Salt Lagoon at deserted house collected by P. Bartsch, August 1930.
Remarks. This is the smallest species so far known in this group. It was very abundant at Lydia Point and at Ocean Bight near the Salt Lagoon. McLean, Shreve and Bartsch found it along about a 12 mile stretch of coast from CanfieldBay to near North East Point.
In general structure it appears to be nearest in relationship to C. scalarinum Pfeiffer from Gibara, Cuba. It does not appear to be at all closely related to C. rehderi Clench and Aguayo, the only other member of the subgenus Umbonis on Great Inagua.
This species is named for Ruth D. Turner, Research Assistant, Department of Mollusks, Museum of Comparative Zoölogy." (Clench & Aguayo, 1952: 423-425)