Fenimorea phasma (Schwengel, 1940) Schwengel, 1940

Fallon, Phillip J., 2016, Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species, Zootaxa 4090 (1), pp. 1-363 : 199-200

Fenimorea phasma (Schwengel, 1940) , new combination

( Plate 95 )

Crassispira phasma Schwengel, 1940: 49 –50; pl. 3, fig. 8: Powell (1966: 76); Abbott (1974: 272; sp. 3037); Turgeon et al. (1998: 104).

Clathrodrillia phasma (Schwengel, 1940) : Williams (2005; 2006; 2009: species 1545).

Not this species or unconfirmed extralimital reports.

Clathrodrillia phasma (Schwengel, 1940) : García (2012a: 65–67) [= Clathrodrillia garciai , n. sp. and Fenimorea tessellata , n. sp., white form]).

Clathrodrillia cf. phasma (Schwengel, 1940) : García (2012a: 65–67 [= Fenimorea alba , n. sp.]).

Type material. Holotype 27.5 x 11.0 mm (ANSP 176453); 2 paratypes in MCZ 207357 (not examined).

Type locality. off Palm Beach, Palm Beach Co., E Florida, in 12 fms [22 m].

Other material examined. 2 spec., 17.9 x 7.3 & 24.0 x 10.0 mm, in 46 m, E of Government Cut, Miami, E Florida (UF 155667).

Range and habitat. E Florida (off Palm Beach Co.; off Miami-Dade Co.). Reported from 22– 46 m.

Description. Shell medium (to 27.5 mm), solid, fusiform, truncated anteriorly, whorls flat around suture, convex below, number up to 9, last approximately 55% of total shell length. Predominant sculptural element is axial ribs. Aperture oval, tapering to a deep anal sinus posteriorly and a very short canal anteriorly. Protoconch worn away on the holotype. Axial sculpture of strong ribs, slightly opisthocline on spire whorls, gathered in to the anterior fasciole on last; ribs greatly reduced in and sharply demarcating the sulcus. Ribs about as wide as their interspaces, 14 on the penultimate and 10 on the last to the varix. Varix hump-like, approximately ⅓-turn from the edge of the outer lip. Spiral sculpture of microscopic spiral incised threads and subequal growth striae that create jagged spirals; pits appear between the striae. This pattern is overlain by widely spaced spiral grooves that terminate in short projections at the edge of the outer lip, about 10, some additional ones may be worn away. Sulcus flat to concave, about ¼ whorl height. Ribs low, slightly curved to reflect anal sinus outline; spiral threads closer than on whorl below. Outer lip thick, flattened from the varix with several strengthening folds; lip edged forms a flat arc from anal sinus to stromboid notch. Anal sinus a deep U-shaped notch on whorl shoulder, constricted somewhat by parietal lobe and outer lip; inner edge of sinus flared outward. Inner lip recumbent, thick anteriorly along canal, developed into a lobe posteriorly on parietal wall. Anterior canal short, open, notched; fasciole not swollen, with the same microsculpture as on shell base. Color white.

Remarks. Taxonomy. Fenimorea phasma first appeared combined in Fenimorea in the USNM on-line database. The holotype has the distinguishing characteristics of Fenimorea : the typical shell surface microsculpture, including overlying spiral grooves that end in projections at lip’s edge, ribs that extend from suture-to-suture but change in the sulcus, a hump-like varix, and a short anterior canal. An all-white specimen is usually suspected of being just a white form of a species that is otherwise colored. F. phasma is not an all-white form of F. j a ne t a e; that species lacks marginal teeth on the outer lip (see Plate 82 ). It more closely matches the white form of F. tessellata , which has marginal teeth; however, that species has more angular shoulders and is known principally from the Gulf of Mexico. Two other specimens believed to be F. phasma , which are in UF 155667, are in better condition. Although possessing shorter spires they are otherwise very similar morphologically. These specimens support the likelihood that F. phasma is a genuine species, and perhaps naturally all-white. Future finds will be important to confirm its validity. Variability. Too few specimens have been examined to describe its natural range in size and form, sculpture and color. The holotype appears to be a gerontic specimen, when compared with the other specimens identified as this species.

Figures

PLATE 82. Fenimorea janetae Bartsch, 1934. Figs. 1 – 2: holotype, off N coast of Puerto Rico (USNM 430249). Fig. 1: ventral, lateral & dorsal views; Fig. 2: apical view, V = varix, L = edge of outer lip. Figs. 4 – 5: off Sapphire Cay, Grand Bahama Is. (USNM 900211); Figs. 6 – 7: Gold Rock, Grand Bahama I. (ANSP 369721); Figs. 3, 8: Turks I., Turks & Caicos Is. (UF 470309). Fig. 3: apical view, V = varix, L = edge of outer lip; Fig. 8: ventral view.

PLATE 95. Fenimorea phasma (Schwengel, 1940). Upper panel. Fig. 1: holotype, off Palm Beach, E Florida (ANSP 176453): ventral, lateral & dorsal views. Lower panel. Figs. 2 – 3: E of Government Cut, Miami, Miami-Dade Co., E Florida (UF 155667).