Cerodrillia sanibelensis, Fallon, Phillip J., 2016

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 : 79

Cerodrillia sanibelensis , new species

( Plate 33 )

Cerodrillia (Cerodrillia) auct. non clappi (Bartsch & Rehder, 1939) : is a misidentification by Perry (1940, pl. 38, fig. 260). Cerodrillia auct. non clappi Bartsch & Rehder, 1939 : is a misidentification by Perry & Schwengel (1955, pl. 38, fig. 260); by Morris (1973: 247, pl. 68, fig. 7); by Abbott & Morris (1995: 256); and by Williams (2005; 2009: 1521 [L photo in R photo pair only]).

Type material. Holotype 9.9 x 4.2 mm, J.S. Schwengel! (MCZ 232475); 7 paratypes, all from the type locality: 3 spec., 10.1 x 4.2, 9.1 x 3.7, & 8.5 x 3.6 mm, J.S. Schwengel! (MCZ 383691); 1 spec., 9.4 x 3.8 mm, J.S. Schwengel! 1940 (ANSP 179391); 3 spec., 13.2 x 5.1, 10.5 x 4.3 & 8.3 x 3.4 mm, Schwengel! 1940 (UF 155624).

Type locality. Sanibel I., Lee County, West Florida, in 7– 13 m.

Other material examined. An additional 6 specimens were examined: 1 spec., 9.6 x 3.9 mm, in 7–11 m, Sanibel I., Lee Co., W Florida, ex B.R. Bales coll., ex J.S. Schwengel coll. (ANSP 221715); 2 spec., 1 measured 12.4 x 4.6 mm, in 9 m W of Naples, Collier Co., W Florida, E. Marcott! Feb 1960 (UF 158169); 1 spec., 11.6 x 4.6 mm, near Cape Romano, Collier Co., W Florida (USNM 150366); 1 spec., 11.7 x 4.8 mm, off Naples, Collier Co., W Florida, D. Steger!, 1966 (ANSP 306487); 1 spec., 10.0 x 4.3 mm, off Sanibel I., Lee Co., 26°26'N, 082°10'W (ANSP 352594); 1 spec. 10.7 x 4.3 mm, in 12 m, S of Big Pine Key, Florida Keys, 24°52.374'N, 81°40.312'W, M. Krisberg! 7 Jun 2009, (M. Krisberg coll.).

Range and habitat. W Florida (off Lee Co.; off Collier Co.); Florida Keys (S of Big Pine Key). Reported from 7– 13 m.

Description. Shell small (to 13.2 mm), broadly fusiform, truncated anteriorly, stout, body whorl approximately 59% of total length, solid; surface appears waxy, of up to approximately 9 barely convex whorls, with whorl periphery below mid whorl. Sculpture of axial ribs. Protoconch of approximately 1¾ smooth whorls, first partially submerged in second. Axial sculpture of low broad ribs that extend from suture-to-suture, broadest and round-crested below mid-whorl on spire whorls, narrower and ridged on shoulder, relatively few in number, 6– 7 on penultimate and 4–6 on last whorl to varix. Spiral sculpture absent except for fine, well-spaced spiral threads on shell base, and distinct ridges on anterior fasciole, strongest anteriorly. Sulcus absent; but axial ribs somewhat reduced and narrowed in the sulcal region. Varix a large cup-handle-like rib behind the anal sinus, producing a lopsided shell profile viewed ventrally. Outer lip thin, projects out a short distance from the varix; some specimens with a strengthening rib near lip edge; stromboid notch weak. Anal sinus deeply notched, U-shaped, positioned on shoulder a little below suture; parietal lobe not constricting the opening. Inner lip emarginated, thick and slightly raised anteriorly, thin in parietal area; and forming a lobe on the parietal wall posteriorly. Anterior canal short, open, unnotched; anterior fasciole not swollen; with approximately 6 spiral ridges. Color solid white, yellowish white or light orange brown; without patterning.

Remarks. Taxonomy. Cerodrillia sanibelensis has all of the key characters of Cerodrillia : an expanded lateral cup-handle-like varix producing an axially lopsided shell; strong ribs that run from suture-to-suture on the spire with little change in the sulcal area; and a waxy smooth shell surface devoid of spiral sculpture, except for lines and ridges on the shell base. Variability. The average length of 14 specimens is 10.36 mm (8.3–13.2 mm), and their average W/ L ratio is 0.407. Identification. Cerodrillia sanibelensis is most easily recognized by its rather straight ribs and solid, waxy appearance. It has fewer axials than congeners of similar size. Cerodrillia sanibelensis is most similar to C. clappi Bartsch & Rehder, 1939 and C. perryae Bartsch & Rehder, 1939 . It differs from both in being broader—the varix is more prominent and spire proportionally shorter, and having fewer axial ribs. From C. perryae it also differs in having whorls that are less convex; the last whorl with a noticeably less angular shoulder, and in lacking color banding.

Etymology. The Sanibel Cerodrillia . Named after the type locality—Sanibel I., Lee Co., W Florida.

Figures

PLATE 33. Cerodrillia sanibelensis, new species. Upper panel. Figs. 1 – 2: holotype, off Sanibel I., Lee Co., W Florida (MCZ 232475). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged view of protoconch (not to scale). Lower panel. Figs. 3 – 8: paratypes from type locality. Fig. 3, 8: UF 155624; Figs. 4, 6 – 7: MCZ 383691; Fig. 5: ANSP 179391.