Strophiops (Strophiops) lacunorum Dall,1905

Original Description

Cerion (Strophiops) inconspicuum new species. Pl. LVIII, figs. 2, 4.

 

Shell small, white or pale brownish, bluntly spindle-shaped, with about two smooth nuclear and six or seven subsequent whorls; apex arcuately tapering; last whorl moderately attenuated, and, at its termination, ascending a little above the middle of the whorl; um­bilicus showing a small open chink; peristome simple, slightly thick­ened and reflected; the ribs are narrow, small, low and separated by about equal interspaces, slightly oblique and very regular; there is no spiral sculpture. The nuclear shell has two short parietal, and one similar basal denticle; the adult has the single parietal denticle short, feeble, and pustular, the axial lamina almost obsolete.

            A variety lacunorum, is larger, heavier, and with the parietal and axial laminae well developed. The measurements are of extremes:

                        Height of

                        Shell                 Aperture           Max Diameter

 

Type. . . . . . . . .  17.0               5.5                    6.5-8.0 mm.

Variety. . . . . . ..  20.0               6.5                    8.5        "

   "        . . . . . . .. 17.5               5.7                    8.5        "

 

Watling Island, U. S. Fish Commission; the variety on the shores of the lagoon by Dr. J. J. Brown; U. S. Nat. Mus., No. 127,494. The types No. 37,676.

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