"Cerion (Strophiops) armouri sp. nov.

(Plate I, figure 4)

            Description.?Shell large, thick, subperforate and ribbed. Color white (shell dead). Whorls 11 ½, flat-sided, last four whorls nearly parallel-sided, other whorls somewhat roundly conic, first 2 ½ whorls smooth, the rest strongly ribbed. Spire acute, produced at an angle of 61°. Aperture ovate. Mid-parietal tooth present. Columellar lamella  not indicated, as the specimen is worn. Lip reflexed and much thickened. Sutures definitely indicated but not deeply indented. Sculpture of very heavy ribs, rather widely spaced, the spaces between them about once and a half the width of the ribs; 18 ribs on the body whorl.

MEASUREMENTS (in millimeters)

Length              Width               Aperture length Aperture width

45                    19.5                 11                                8               Holotype

            Holotype, Mus. Comp. Zoöl., no. 101,163, south coast of Mariguana Island, Bahamas, Barbour, Fairchild and Greenway, collectors (February, 1933.)

            It differs from both C. barbouri and C. mariguanense by its much larger size and by the possession of very heavy ribs.

            It is of course quite possible that these three species from Mariguana may all be very intimately related, and there may be intermediate forms that will show a complete series of gradations. The few specimens obtained were picked up over a fairly large area, and not all found in one place."