Cerodrillia girardi Lyons, 1972

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 : 67-69

Cerodrillia girardi Lyons, 1972

( Plate 27 )

Cerodrillia girardi Lyons, 1972: 3 –4, figs. 1, 2: Turgeon et al. (1988: 96); Bieler & Bradford (1991); Turgeon et al. (1998: 102); Boyko & Cordeiro (2001: 29); Williams (2005; 2006; 2009: 1523 [in part, North Carolina occurrence doubtful]); Rosenberg et al. (2009 [in part, North Carolina occurrence = Douglassia bealiana Schwengel & McGinty, 1942 ]).

Type material. Holotype 8.9 x 4.2 mm, W. Lyons!, 11 Aug 1966 (USNM 707001); single paratypes, all W. Lyons! and from the type locality but collected on different dates: 9.8 x 4.3 mm (MCZ 278870) and 8.8 x 3.8 mm (ANSP 324019). Additional paratypes not examined for this work are in: LACM 1551, AMNH 167028, DMNH 47901, and FSBC I (Lyons, 1972: 3–4).

Type locality. Project Hourglass Sta. D, 27°37'N, 83°58'W, off Egmont Key, W Florida, in 55 m.

Other material examined. An additional 33 specimens were examined: Alabama: 1 spec., 4.4 x 2.2 mm, in 122 m, offshore, 29°214'N., 088°15'W, E. García! aboard R/V Pelican, 15 Oct 1994 (EFG 14604). W Florida: 1 spec., 10.2 x 4.7 mm, in 55 m, SW of Panama City, Bay Co., J. Moore! (EFG 11567); 1 spec., 10.1 x 4.7 mm, in 55 m, off Cedar Key, Levi Co., J. Moore! Jun 1964 (UF 149075); 2 spec., 8.8 x 4.0 & 8.0 x 3.8 mm, in 73 m, 95 mi [153 km] W of Egmont Key, Hillsborough Co. (author’s coll.); 2 spec., 9.9 x 4.4 & 5.0 x 2.6 mm, in 73 m, 95 mi [153 km] W of Egmont Key, Hillsborough Co., 27°34'N, 084°15'W, R. Dillon! 1972 (ANSP 395092);4 spec., 9.7 x 4.6, 9.8 x 4.5, 8.1 x 3.8 & 3.9 x 2.1 mm, in 73–91 m, SW of Egmont Key, Hillsborough Co., McGinty! Sep 1963 (UF 169897); 2 spec., 7.3 x 3.3 & 6.1 x 3.1 mm, in 66 m, about 143 km W of Egmont Key, Hillsborough Co., 27°36.81'N, 84°13.04'W, E. García! aboard R/V Pelican, 13 Aug 1994 (EFG 14489); 2 spec., 8.6 x 3.9 & 8.6 x 4.2 mm, in 219 m, W of Ft. Myers, Lee Co. (H.G. Lee coll.); 3 spec., 6.7 x 3.4, 5.7 x 3.5 & 9.0 x 4.4 mm, in 82 m, SW by S of St. Johns Pass, Collier Co., Powlus! Apr 1958 (UF 158085); 8 spec., the best 5: 6.6 x 3.1, 6.6 x 3.0, 8.3 x 3.7, 8.0 x 3.5 & 9.1 x 4.2 mm, Gulf of Mexico off Florida, J. Moore! (USNM 900118); 1 spec., 7.4 x 3.6 mm, in 55 m, Gulf of Mexico, J. Moore! (USNM 900119). Florida Keys: 1 spec., 8.4 x 4.9 mm, in 75 m, 21 km SW of Key West (EFG 19601); 4 spec., the best 3: 8.7 x 4.0, 4.9 x 2.4 & 7.6 x 3.5 mm, in 85 m, off Dry Tortugas, R.C. Hoerle! 1968 (USNM 822922); 1 spec., 7.8 x 3.7 mm, in 110 m, SSE of channel buoy, Eolis Station 5, 1910, Key West (USNM 411079).

Range and habitat. Alabama; W Florida (off Levi Co.; off Hillsborough Co.; off Lee Co.; off Collier Co.); Florida Keys (off Key West; off Dry Tortugas). Reported taken from 46–219 m, but most reports fall in the range of 46– 73 m. Lyons has observed that C. girardi appears most often in the Lithothamnion zone at 30 fathoms [55 m] over its known range (Lyons, pers. comm.).

Description. Shell small (to 12.8 mm total length), broadly fusiform, waxy smooth, up to about 7 ½ distinctly convex whorls, the last sub-globose and approximately 64% of total length. Shell sculpture of broad axial ribs; aperture sub-oval, with a deep anal sinus posteriorly and short canal anteriorly. Protoconch of 2 smooth, round whorls.

Axial sculpture of bold ribs that run from suture-to-suture on spire whorls, and evanesce below periphery of last whorl; 7–8 on penultimate and 6–8 on last to varix. Ribs curved on spire, somewhat sigmoid on base; crests round; intercostal space about as wide as ribs. Growth striae run oblique to ribs; present throughout. Varix prominent, cup handle-like, just behind the anal sinus. Spiral sculpture of spiral lines on anterior portion of base, ridges on anterior fasciole. Remainder of shell smooth. Sulcus absent. Outer lip thin, projecting out from the base of the varix, rather narrow. Edge of lip from and congruent with the anal sinus to the anterior canal forms a flat arc, with a shallow indentation a ruffle at the stromboid notch. The width of the lip widest just below anal sinus, then narrows toward the anterior canal. Anal sinus deep, U-shaped, bordered by parietal callus, entrance not constricted. Inner lip recumbent except on the columella where it is erect, emarginated, thin and moderately wide, formed into a lobe posteriorly, on the parietal side of the anal sinus. Anterior canal very short but distinct, broad, unnotched. Anterior fasciole not swollen. Color a uniform light to dark amber.

Remarks. Taxonomy. Cerodrillia girardi has all the characteristics of Cerodrillia : axial ribs that run from suture-to-suture on the spire, a stout shell with short anterior canal, a cup-handle-like varix located just behind the anal sinus, a smooth shell with spiral lines limited to the shell base, and threads on the anterior fasciole. It is unique in possessing a large, rather globose last whorl. Variability. According to Lyons (1972: 3) length to 12.8 mm; the largest examined in this study is 10.2 mm. The average total length of 32 measured specimens is 7.89 mm (3.9– 10.2 mm), and their average W/ L ratio is 0.480. Some variability in color occurs—from uniform light to dark amber. Identification. No other occurrences of this species have been reported in the literature since its description by Lyons. Several factors may explain its rarity—it appears to be limited to a relatively narrow depth range in the eastern Gulf of Mexico, it is small and easily confused with at least two other species: Douglassia bealiana Schwengel & McGinty, 1942 and C. ambigua , new species, the latter from the E coast of Florida. Cerodrillia girardi is distinctive with its globose last whorl and relatively short spire (last whorl approximately 64% of total length. It is similar to D. bealiana but differs in possessing a 2-whorl protoconch, not 3 as in D. bealiana , is larger (average length 7.89 versus 6.83, and lacks the white mid-whorl band. From C. ambigua it differs in being smaller (7.89 versus 9.12 mm average total length), in possessing more angular shoulders, especially the last whorl, and having a proportionally larger last whorl (64 versus 59% of total length). From C. perryae it differs in being smaller (average length 8.26 versus 9.78, and in possessing a dark amber, not white base shell color.

Figures

PLATE 27. Cerodrillia girardi Lyons, 1972. Upper panel. Figs. 1 – 3: holotype, off Egmont Key, W Florida (USNM 707001). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged views of the protoconch (not to scale); Fig. 3: apical view, V = varix, L = edge of outer lip. Lower panel. Figs. 4 – 5, 7, 14: Gulf of Mexico (USNM 900118). Lip of protoconch visible on the right side of the 2 nd whorl of the young specimen in Fig. 5. Figs. 6, 9: W of Egmont Key, Hillsborough Co., W Florida (author’s coll.); Figs. 8, 12: W of Ft. Myers, Lee Co., W Florida (H. G. Lee coll.); Figs. 10, 15: off Dry Tortugas, Florida Keys (USNM 822922); Fig. 11: paratype, type locality (MCZ 278870); Fig. 13: SW of Egmont Key, Hillsborough Co. (UF 169897); Fig. 16: SW by S of St. Johns Pass, Collier Co., W Florida (UF 158085).