Neodrillia crassa Fallon, 2016, new species
Creators: name: Fallon, Phillip J.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Neogastropoda
Drilliidae
Neodrillia
Neodrillia crassa

description: 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.
description: Published as part of Fallon, Phillip J., 2016, Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species, pp. 1-363 in Zootaxa 4090 (1) on pages 265-267, DOI: 10.11646/zootaxa.4090.1.1, http://zenodo.org/record/263299