Neodrillia blakensis (Tippett, 2007) Tippett, 2007

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 : 263-265

Neodrillia blakensis (Tippett, 2007) , new combination

( Plate 134 )

“(?) Turridae sp.” of Lamy & Pointier (2001: 22, 73, photo p. 26) is likely this species according to Tippett (2007: 210). Drillia (Clathrodrillia) blakensis Tippett, 2007: 210 –213, figs. 1–3, 8.

Fenimorea species: Sunderland & Sunderland (1999: 17, text photograph [northern Bahama Is.]).

Type material. Holotype 44.8 x 16.0 mm (USNM 900034); 3 paratypes from the type locality: 45.4 x 16.0, 44.0 x 14.6 & 42.7 x 15.7 mm (USNM 1096708). All types dredged by R/V Oregon at type locality (Tippett, 2007: 211).

Type locality. Blake Plateau, at 400– 450 m.

Other material examined. An additional two specimens were examined: 1 spec., 41.6 x 14.8 mm, in 46 m on coral sand & rubble at base of cliff., 0.4 km W of entrance to Santa Marta Lagoon, Curaçao, R. Masino! (author’s coll.); 1 spec., 46.2 x 17.4 mm, off St. Luce, Martinique, from dry fisherman’s net, R. Delannoye! (R. Delannoye coll.).

Range and habitat. Off SE United States (Blake Plateau); Saba I.; Martinique; Netherlands Antilles ( Curaçao). The Curaçao specimen (Pl. 134, Fig. 7) represents an extension of its previously reported range. If the specimen illustrated in Sunderland & Sunderland (1999: 17) is this species, then its range would also include the northern Bahama Is. The type specimens have been reported from bathyal depths (> 200 m); however, the Saba and Curaçao specimens from shelf depths (46–150 m). The Curaçao specimen (from 46 m), an empty shell, may have been transported to a relatively shallow depth by offshore fishermen emptying their gear (bathyal depths occur within a few kilometers of its northern coast). Nonetheless the find places the species in the proximity of the island.

Description. Shell medium (to approximately 48 mm), fusiform with a tall spire and moderately long anterior canal; whorls convex, bulging, number to 10, last whorl approximately 59% of total shell length; predominant sculpture of axial ribs. Aperture narrow, slightly wider at its widest point than the anal sinus and anterior siphon. Protoconch decollated on holotype; none of the other specimens examined had intact protoconchs. Axial sculpture of ribs that extend from suture-to-suture on spire whorls, evanesce just below periphery of last whorl; 12–13 on the penultimate whorl, 8–11 on the last to the varix, interspaces about as wide as rib width. Ribs straight on spire whorls, opisthocline on the last; greatly reduced in sulcus; rib crests ridged, not round. Growth striae fine but dense, most visible between ribs. Varix large and protruding, approximately ⅓-turn from edge of outer lip. Spiral sculpture of coarse evenly spaced raised spiral threads that override ribs, approximately 13 on penultimate and 8– 11 more on last whorl from suture line to anterior fasciole. Spaces separating threads wider than thread diameter; threads incised on their adapical side resulting in a saw-tooth (slanted adapically) formation; threads are weak in sulcus and on shell base. Sulcus narrow, concave; ribs greatly reduced, obsolete on last whorl, and spiral threads weak. Outer lip thin, flattened from varix to lip edge, strengthened by up to 8 weak axial folds. Lip edge smooth, not scalloped; forms a low arc from anal sinus to stromboid notch, where it rounds off into the notch. Anal sinus deep, U-shaped, projects upward, appearing spout-like on account of the constriction of the parietal tubercle and upward projection of outer lip. Inner lip thick, margined, erect anteriorly along columella and extending anteriorly slightly beyond columella, recumbent on parietal wall; formed into a low lobe posteriorly. Anterior canal moderately long for the genus, open, turned to the right when viewed ventrally; tip slightly notched; fasciole not swollen but a bulge, or twist, forms in older specimens as the canal orientation rotates during shell growth. A false umbilicus may be present between the fasciolar twist and inner lip. Color off white with a broad light-brown midwhorl band darkest on shoulder between ribs, over lower shell base, and anterior fasciole. A few irregular blotches of a slightly darker shade may be present on spire whorls in intercostal spaces, and on the varix.

Remarks. Taxonomy. Neodrillia blakensis has the principal characteristics of Neodrillia : shell surface with regularly spaced coarse raised spiral threads, made coarse by the intersection of growth striae; numerous low axial ribs that are considerably reduced in the sulcus; a narrow aperture; spout-like anal sinus, and a large, protruding varix. Variability. The average total length of eight specimens is 44.24 mm (41.2–48.0 mm) and the average W/ L ratio of seven specimens is 0.360. Identification. Neodrillia blakensis is the largest TWA Neodrillia and is further distinguished from N. princeps , new species, its closest congener, in possessing a longer anterior canal, somewhat rounder base whorl, more oblique ribs, and round, bulging whorls. Neodrillia princeps is also large (to 46.6 mm) but has less convex whorls. From large Fenimorea (F. j an e t a e Bartsch, 1934, F. kathyae Tippett, 1995 , and F. sunderlandi [Petuch, 1987]) it can be distinguished by its elongate siphonal canal and opisthocline ribs. Fenimorea has a short anterior canal and straight ribs.

Figures

PLATE 134. Neodrillia blakensis (Tippett, 2007). Upper panel. Figs. 1 – 2: holotype, Blake Plateau, off SE USA (USNM 900034). Fig. 1: ventral, lateral & dorsal views; Fig. 2: apical view, L = edge of outer lip, V = varix. Varix somewhat atypical on holotype. Fig. 3. apical view of shell depicted in Fig. 7: L = edge of outer lip, V = varix. Lower panel. Figs. 4 – 6: paratypes, Blake Plateau, off SE USA (USNM 109670); Fig. 7: off Santa Marta, Curaçao, Netherlands Antilles (author’s coll.); Fig. 8: off St. Luce, Martinique (R. Delannoye coll.).