Fenimorea mackintoshi, 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 : 181

Fenimorea mackintoshi , new species

( Plate 85 )

Types. Holotype 13.0 x 4.6 mm, G. Mackintosh!, 15 Mar 1996 (USNM 1291349); 15 paratypes: 1 spec., 12.5 x 4.6 mm, from type locality, G. Mackintosh!, 15 Mar 1996 (USNM 1291350); 13 spec: 13.7 x 5.1, 12.8 x 4.7, 13.9 x 5.1, 13.2 x 5.0 & 13.7 x 5.0 mm (ANSP 464990), 12.5 x 5.0, 13.4 x 4.8, 12.6 x 4.6, 13.4 x 5.2 mm (UF 496642), 12.3 x 4.6, 12.3 x 4.5, 12.3 x 4.4 & 15.3 x 5.5 mm (author’s coll.), in 6.4 m, S end of Highborne Cay, Exuma, Bahama Is., G. Mackintosh!, 17 Mar 1996; 1 spec., 14.9 x 5.9 mm, at 12 m, Start Bay, Mayaguana I., Bahama Is., G. Mackintosh!, 18 Feb 1993 (author’s coll.).

Type locality. W side of Allen’s Cay, Exuma, Bahama Is., in 6.4 m.

Other material examined. 1 spec., 13.1 x 5.0 mm, at 3 m, Honeymoon Cove, Gun Cay, Bimini Is., G. Mackintosh! 8 Apr 1994 (author’s coll.).

Range and habitat. Bahama Is. (Gun Cay, Bimini Is.; Allan’s and Highborne Cays, Exuma; Mayaguana I.) in 3– 12 m.

Description. Shell small (to 15.3 mm), fusiform, truncated anteriorly, to approximately 9 whorls; body whorl large compared to spire whorls, approximately 58% of total shell height. Protoconch of 2 smooth round whorls, the first only slightly smaller in diameter than second. Axial sculpture of weak, narrow ribs on first, strong on second and succeeding whorls, extending from suture-to-suture, abruptly narrowed, arcuate, and reduced in the sulcus, forming a distinct shoulder at the edge of the sulcus. Ribs about as wide or less than their interspaces; most slightly opisthocline overall, 12–13 on the penultimate whorl, 7–11 to the varix on the body whorl. Microscopic growth striae are present throughout, but finer compared with other members of the genus. Varix broad, hump-like, ⅓-turn back from edge of outer lip. Spiral sculpture consisting of a microsculpture of fine parallel jagged lines closely spaced in sulcus, more widely spaced anterior to the shoulder (approximately 4/mm on body whorl), together with fine axial striae that form shallow pits on shell surface. Sulcus wide, about ¼- to ⅓-whorl height; slightly convex with rib traces curved in an arc reflecting the outline of the anal sinus. Outer lip thin, smooth-edged, forming a gentle continuous curve from the anal sinus to the canal tip; strengthened by up to four irregular axial folds between the varix and edge of outer lip; not toothed but with small crenulations along its inside edge; stromboid notch shallow. Anal sinus deep, sinus angled away from the suture by a parietal callus. Inner lip margined; thickest on the anterior canal, thin in the parietal area, and forming a thick parietal callus near the junction with the outer lip. Anterior canal short, deeply channeled and notched; twisted to the left viewed ventrally; anterior fasciole slightly swollen, its surface marked by spiral ridges. Color an uneven brown with lighter and darker areas, except apex (protoconch and first teleoconch whorl), anterior fasciole, and distal end of anterior canal, which are white. Darker brown in a band on the top of the shoulder and between the ribs; rib crests and anterior halves of the whorls lighter brown. Some specimens have irregular patches of white or broken white bands.

Remarks. Taxonomy. Fenimorea mackintoshi exhibits all of the critical characteristics of Fenimorea : numerous ribs from suture-to-suture but transformed in the sulcus, surface microsculpture typical for the genus, and varix hump-like about ⅓-turn from the edge of the outer lip. It is unique for the genus in its coloration and in possessing a relatively narrow shell. Variability. The specimens vary little in color; some exhibit faint white bands on whorl shoulder or irregular patches, but otherwise quite uniform. The average length of 17 measured specimens is 13.23 mm (12.3–15.3 mm), their average W/ L ratio is 0.372. The specimens vary by only 3 mm in length, and are relatively slim for the genus. Identification. Specimens of F. mackintoshi first appear to be small or oddlycolored F. f u ca t a because of its similarity in shell sculpture and color; however, it differs in a number of ways. The protoconch whorls are more evenly sized, not tapering; the teleoconch is slenderer; the microscopic spiral lines are not as numerous and variable as in F. f u c at a; the axial growth lines are not as prominent; and the outer lip lacks projecting teeth. From F. jongreenlawi , new species and F. caysalensis , new species it differs in size, shell shape, shell microsculpture, and in coloration.

Etymology. Gary Mackintosh’s Fenimorea . Named for Gary Mackintosh who collected all of the specimens studied here, and for the contribution to science his efforts have yielded.

Figures

PLATE 85. Fenimorea mackintoshi, new species. Upper panel. Figs. 1, 3: holotype, W side, Allan's Cay, Exuma, Bahama Is. (USNM 1291349). Fig. 1: ventral, lateral, & dorsal views; Fig. 3: apical view, V = varix, L = edge of outer lip. Fig. 2: enlarged view of protoconch of specimen in Fig. 9 (not to scale). Lower panel. Fig. 4: paratype, W side, Allan's Cay, Exuma, Bahama Is. (USNM 1291350); Figs. 5 – 11: paratypes, S end, Highborne Cay, Exuma, Bahama Is.: Figs. 5 – 9: ANSP 464990; Figs. 10 – 11: author’s coll.; Fig. 12: Honeymoon Cove, Gun Cay, Bimini Is., Bahama Is. (author’s coll.); Figs. 13 – 17: S end, Highborne Cay, Exuma, Bahama Is.: Figs. 13 – 16: UF 496642; Fig. 17: author’s coll.