Fenimorea jongreenlawi, 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 : 177

Fenimorea jongreenlawi , new species

( Plate 83 )

Types. Holotype 12.3 x 5.0 mm, G. Mackintosh! 14 Jul 1996 (USNM 1291347); 32 paratypes: 2 spec., 10.4 x 4.4 & 9.9 x 4.2 mm, in 6 m, Charlestown Bay, Canouan I., SVG, G. Mackintosh!, 7 Aug 1997 (USNM 1291348); 5 spec., 11.8 x 4.6, 10.5 x 4.4, 10.6 x 4.6, 10.3 x 4.4 & 10.4 x 4.3 mm, in 4.6 m, Dove Cay, Canouan I., SVG, G. Mackintosh!, 6 Jun 2004 (ANSP 464987); 2 spec., 12.0 x 4.7 & 11.4 x 4.6 mm, in 8 m, Petit Nevis I., SVG (ANSP 464983); 4 spec., 10.6 x 4.2, 11.4 x 4.3, 10.5 x 4.5 & 10.3 x 4.0 mm, in 8 m, Petit Nevis I., SVG (BMSM 14990); 6 spec., 12.2 x 5.0, 11.4 x 4.6, 11.4 x 4.3 mm (UF 496639), 10.3 x 4.3 mm (UF 496640), 10.8 x 4.5 & 11.6 x 4.6 mm (UF 496641), in 8–9 m, Petit Nevis I., SVG; 6 spec., 11.0 x 4.5, 11.2 x 4.3, 11.7 x 4.5, 12.2 x 5.0, 9.7 x 4.0 & 9.9 x 4.0 mm, in 8–9 m, Petit Nevis I., SVG (MZSP 122066); 6 spec., 9.8 x 3.8, 10.8 x 4.3, 10.7 x 4.5, 11.2 x 4.3, 12.3 x 5.0 & 10.0 x 4.0 mm, in 8–9 m, Petit Nevis I., SVG (author’s coll.); 1 spec. 10.4 x 4.2 mm, in 8–9 m, Petit Nevis I., SVG, G. Mackintosh! (P. Stahlschmidt coll.).

Type locality. Petit Nevis I., SVG, in 8 m.

Other material examined. 1 spec., 9.3 x 4.0 mm, 0.8 km W of Pigeon Pt., Tobago I., Trinidad & Tobago, R. Masino! (author’s coll.).

Range and habitat. SVG (Canouan I.; Petit Nevis I.); Trinidad & Tobago ( Tobago I.). Reported from 6– 9 m.

Description. Shell small (to 12.3 mm in total length), stoutly fusiform, bullet-shaped, with a short, acuminate spire and truncated last whorl; to about 8¼ whorls, slightly convex on spire, last whorl approximately 64% of shell length. Axial sculpture dominates. Protoconch paucispiral, of 2 smooth round whorls, the second bulging, edge slightly beyond suture with first teleoconch whorl. Axial sculpture of low, round ribs that extend from suture-tosuture, slightly reduced and curved in the sulcus, evanescing on shell base. Ribs number 11–15 on penultimate and 6–9 on last whorl to the varix. Ribs about as wide as their interspaces. Growth striae cover shell surface; striae on trailing sides run parallel with ribs; striae on leading side cross over ribs obliquely at rib shoulders, thence to suture, slightly arcuate in sulcus. Spiral sculpture of very fine threads, more closely spaced in sulcus, becoming slightly ridge-like on shell base and anterior fasciole. These are made jagged by intersecting, more closely spaced growth striae creating spirally aligned rectangular pits between the threads, the characteristic microsculpture of Fenimorea . Larger, more widely spaced spiral grooves are lacking. Sulcus demarcated with a crease anteriorly, with low, slightly convex, arcuate ribs, spiral lines and growth striae. Vari x broad, hump-like, ⅓-turn back from the edge of the outer lip. Outer lip projecting, somewhat flattened from the varix to its edge; smooth, without teeth, with a weak indentation anteriorly for a stromboid notch. Anal sinus deep, close to suture, round at its apex, partially constricted at its opening by a parietal callus and projection of outer lip. Inner lip margined, thickest anteriorly, thin on the parietal wall, formed into a parietal lobe posteriorly. Anterior canal short, open, slightly notched, anterior fasciole not swollen. Color white with light brown band below periphery; darker brown in intercostal spaces, patches on sulcus, and varix.

Remarks. Taxonomy. Fenimorea jongreenlawi has all the traits of the genus: shell surface microsculpture typical for the genus, ribs suture-to-suture that are modified in the sulcus, a broad, hump-like varix, and a deep Ushaped anal sinus. It is unique for its small size and coloration. Variability. The 34 examined specimens have an average total length of 10.87 mm (9.3–12.3 mm) and an average W/ L ratio of 0.405. While the specimens from SVG are very similar in color, a single specimen from Tobago I. is more orange in color. It is not known if this single representative is typical of the Tobagoan population. Identification. Fenimorea jongreenlawi is similar to F. caysalensis , new species, F. biminensis , new species, F. glennduffyi , new species, F. culexensis, Usticke, 1969 , and F. fabae , new species. From F. caysalensis it differs in being less stout (W/L = 0.405 versus 0.449), in possessing slightly fewer axials (11–15 versus 12–18 on the penultimate whorl), and in having a smooth, not scalloped outer lip. Also, F. caysalensis is more darkly colored. From F. bimensis and F. glennduffyi it differs in lacking minute “teeth” on the edge of the outer lip, is a paler brown color, and has a slightly acuminate spire tip, which is not so in F. biminensis and F. glennduffyi . From F. culexensis it differs in being smaller (10.87 mm versus 11.97 mm average total length), in lacking spiral grooves on the last whorl, in possessing a round not squarish base, and in coloration. From F. fabae it differs in being larger (10.87 versus 8.99 mm average total length), in possessing ribs and a more streamlined profile. It also has a different color pattern.

Etymology. Named in honor of Dr. Jon Greenlaw, ornithologist and conchologist, who was hugely influential in stimulating my interest in molluscan taxonomy.

Figures

PLATE 83. Fenimorea jongreenlawi, new species. Upper panel. Figs. 1, 3: holotype, Petit Nevis I., SVG (USNM 1291347). Fig. 1: ventral, lateral and dorsal views; Fig. 3: apical view, V = varix, L = edge of outer lip. Fig. 2: enlarged view of protoconch of specimen in Fig. 7 (not to scale). Lower panel, Figs. 4 – 26: paratypes. Figs. 4 – 5: Charlestown Bay, Canouan I. (USNM 1291348); Figs. 6 – 7: Dove Cay, Canouan I. (ANSP 464983); Figs. 8 – 9: Petit Nevis I. (ANSP 464987); Figs. 10 – 13: Petit Nevis I. (BMSM 14990); Fig. 14: Petit Nevis I. (UF 496639); Fig. 15: Petit Nevis I. (UF 496640); Figs. 16 – 17: Petit Nevis I.: (UF 496641); Figs. 18 – 21: Petit Nevis I. (MZSP 122066); Figs. 22 – 26: Petit Nevis I. (author’s coll.). Fig. 27: W of Pigeon Pt., Tobago I. (author’s coll.).