Cerion (Umbonis) shrevei Clench and Aguayo, 1952

Original Description

"Cerion (Umbonis) shrevei, new species

Plate 57, fig. 4

Description. Shell rimately perforate, solid, elongate, sculp­tured and reaching about 33 mm. (It inches) in length. Whorls 10 to 11, moderately convex and slightly angled. Color a dull gray. Spire broadly conic, moderately convex at the summit, variable, and produced at an angle of about 70°. Aperture sub­circular to subovate. Parietal tooth rather large and centrally located. Columellar tooth small and positioned well within the aperture. Outer lip reflected backwards, though only shortly so. Parietal or inner lip consisting of a strongly developed straight ridge. Suture but slightly indented. Sculpture con­sisting of numerous and fine axial costae, variable as to their development and number. There are 65 on the body whorl of the holotype. Spiral sculpture consisting of numerous and fine incised lines; though variable they generally cut through the axial costae. First whorl smooth, the next finely axially cos­tate, the following whorls more strongly axially costate.

 

  length               width                    whorls

28                    12.8 mm.              10 ½                        Holotype

31                       12     .                10 ½                       Para type

33.2                    13.5                   11                            "

27.1                    12.5                   10 ½                        "

25.5                    12                      10                            "

 

Types. Holotype, Museum of Comparative Zoology, no. 192287, from near Northwest Point, Little Inagua Island, Ba­hama Islands. R. A. McLean and B. Shreve, collectors, 1938. Additional paratypes in the Museum of Comparative Zoology, the Museo Poey, the United States National Museum and the Museum of Zoology, University of Michigan.

 

Remarks. This species does not seem to be closely related to any other in the scalarinum complex. The axial costae are fine and numerous, the spiral incised lines are coarse and rather deeply cut into the shell. It is, perhaps nearest to C. palmeri Sanchez Roig, at least in its shell characters. It differs in being less attenuate and in having both the axial costae and incised lines much stronger.

 

Records. BAHAMA ISLANDS: near Northwest Point, Little Inagua (MCZ); Northwest Point and halfway between West and South Points, Little Inagua (both USNM)."   (Clench & Aguayo, 1952:436-438)

 

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