Neodrillia crassa, 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 : 265-267

Neodrillia crassa , new species

( Plate 135 )

Drillia pagodula auct. non Dall, 1889: 90: is a misidentification by Dall of specimens from R/V Blake Sta. 177, off Dominica, and R/V Blake Stas. 282, 223 (in part), and 280, off Barbados.

Drillia albicoma auct. non Dall, 1889: 83–84: is a misidentification, in part, by Dall of fragments from off Barbados, R/V Hassler Exped. off Barbados, and R/V Blake Sta. 45, off Barbados.

Cymatosyrinx pagodula (Dall, 1889) : is a misidentification by Sander & Lalli (1982: 317 [ Barbados]).

Type material. Holotype 20.6 x 6.8 mm (USNM 87472), also a syntype of Drillia pagodula, Dall, 1889 ; lip missing to varix; 7 paratypes: 2 paralectotypes of Drillia albicoma Dall, 1889 : 19.3 x 6.5 mm, (USNM 87462) and 10.6 x 4.2 mm (MCZ 7059), both from 183 m, R/V Hassler expedition; 1 spec., 17.8 x 5.8 mm, in 200 m, off Holetown, St. James Parish, Barbados, 13°10'52''N, 059°38'30''W, F. Sander! Nov 1978 (ANSP 353515); 4 spec., 26.8 x 10.0, 21.3 x 8.6, 18.6 x 7.2 & 17.2 x 6.5 mm, in 244–274 m, in old bottle off Sea Aquarium, Bapor Kibra, Willemstad, Curaçao, Netherlands Antilles, 12°04'59.51"N, 68°53'56.61"W, C. Baldwin! aboard submersible Curasub , 8 Feb 2013 (USNM 1231400).

Type locality. Off Dominica, 15°32′18″N, 061°30′10″W, in 118 fms [216 m] (R/V Blake Sta. 177).

Other material examined. An additional nine specimens were examined: 2 spec., 11.3 x 4.2 & 11.2 x 4.1 mm, in 118 fms [216 m] R/V Blake Sta. 117 off Dominica, 15°32′18″N, 061°30′10″W (USNM 1291373), 4 paralectotypes of Drillia pagodula Dall, 1889 : 9.8 x 3.7, 8.5 x 3.7, 8.0 x 3.4 & 6.9 x 3.0 mm, in 103 fms [188 m], R/V Blake Station 273, 1878, off Barbados (MCZ 7069); 1 paralectotype of D. pagodula Dall, 1889 : 14.0 x 5.2 mm, in 154 fms [282 m], R/V Blake Station 282, 1878, off Barbados, (MCZ 7068); 1 paralectotype of D. pagodula Dall, 1889 : 9.6 x 3.8 mm, in 73 fms [134 m], R/V Blake Station 290, 1878, off Barbados, (MCZ 7070); 1 spec., 15.7 x 5.3, in 200 m, off Holetown, St. James Parish, Barbados, 13°10'52''N, 059°38'30''W, F. Sander! Nov 1978 (ANSP 353514).

Range and habitat. Dominica (offshore); Barbados (offshore); Netherlands Antilles (off SW Curaçao). Reported from 134– 282 m.

Description. Shell medium (to 26.8 mm in total length), fusiform, truncated anteriorly with a tall spire and a short, narrow anterior canal; shell surface dull, granular-looking. Whorls nearly straight-sided, up to about 11½ total, the last 55% of total length. Sculpture of low, narrow ribs. Protoconch eroded on holotype, of 2¼ whorls on juvenile paratype. Lost or eroded on all the other paratypes. Axial sculpture of low, narrow, opisthocline ribs that run from suture-to-suture on the spire whorls and to anterior fasciole on last; slightly recurved on whorl shoulders reflecting past positions of anal sinus. Ribs number 15 on penultimate, and 10 on last whorl to varix; intercostal space greater than rib width. Varix large, convex, wider and much higher than adjacent ribs, but not hump-like. Spiral sculpture of closely-packed heavy raised threads roughened by growth striae. Threads override ribs. Sulcus slightly concave, ribs recurved, just a little lower than on whorl proper. Outer lip “peeled” back to varix by predator on holotype and the larger paratypes Anal sinus mostly missing on holotype; a deep laterally-directed notch on some paratypes. Inner lip moderately wide, recumbent, margined, pinched erect anteriorly, and formed into a weak callus posteriorly where it joins the outer lip. Anterior canal moderately long, open, unnotched; anterior fasciole not swollen. Fasciole sculpture is the same as shell base but spiral threads heavier and wider apart. Color white with a broad, light golden-brown band from the sulcus to the suture of the succeeding spire whorls, to the lower part of the shell base of last whorl; varix with a darker yellow-brown patch; aperture porcellaneous white.

Remarks. Taxonomy. Neodrillia crassa has the characteristic shell surface microsculpture of Neodrillia : closely-packed raised spiral threads roughened by growth striae, a tall spire, and low, slightly opisthocline ribs. Variability. The 17 complete specimens have an average total length of 14.54 mm (6.9–26.8 mm), their W/ L ratio is 0.379. Most shells have some degree of predator damage, the largest specimens with lips chipped back to the varix such that no complete description of a fully developed outer lip is possible. Identification. Among its congeners, N. crassa is most like N. albicoma (Dall, 1889) but differs in being stouter and a light golden brown in base color, not white. It is also similar to Fenimorea pagodula (Dall, 1889) but differs in detail of the microsculpture, has a broader shell (W/ L ratio = 0.381 versus 0.330), and more axials (13–15 versus 9–11 on the penultimate whorl). Both can have a faded yellow to orange mid-whorl spiral band, although it is usually more subdued in N. crassa .

Etymology. The Coarse Neodrillia , named for the rough shell surface and appearance of examined specimens. From the Latin adjective crassus, feminine crassa , meaning coarse.

Figures

PLATE 135. Neodrillia crassa, new species. Upper panel. Figs. 1, 3: holotype, off Dominica (USNM 87472). Fig. 1: ventral, lateral & dorsal views; Fig. 3: apical view, V = varix; Fig. 2: enlarged view of protoconch (not to scale) of specimen in Fig. 7. Lower panel. Figs. 4 – 8, 10 – 11: paratypes. Figs. 4, 5, 7 & 10: off Sea Aquarium, Curaçao, Netherlands Antilles (USNM 1231400); Fig. 6: off Barbados (USNM 87462); Figs. 8, 9: off Holetown, Barbados (ANSP 353515 and ANSP 353514, respectively); Fig. 11: off Barbados (MCZ 7059); Fig. 12: off Barbados (MCZ 7068); Fig. 13: off Barbados (MCZ 7070); Figs. 14 – 17: off Barbados (MCZ 7069); Figs 18 – 19: off Dominica (USNM 1291373).