Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species
Fallon, Phillip J.
Zootaxa
2016
4090
1
1
363
6S88W
[151,356,1231,1257]
Gastropoda
Drilliidae
Neodrillia
Animalia
Neogastropoda
264
265
Mollusca
species
crassa
sp. nov.
Drillia albicomaauct. non Dall, 1889: 83–84: is a misidentification, in part, by Dall of fragments from off Barbados, R/V HasslerExped. off Barbados, and R/V BlakeSta. 45, off Barbados. Cymatosyrinx pagodula(Dall, 1889): is a misidentification by Sander & Lalli (1982: 317 [ Barbados]).
Typematerial. Holotype20.6 x 6.8 mm(USNM 87472), also a syntypeof Drillia pagodula, Dall, 1889; lip missing to varix; 7 paratypes: 2 paralectotypesof Drillia albicomaDall, 1889: 19.3 x 6.5 mm, (USNM 87462) and 10.6 x 4.2 mm(MCZ 7059), both from 183 m, R/V Hasslerexpedition; 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). Typelocality.Off Dominica, 15°32′18″N, 061°30′10″W, in 118 fms [ 216 m] (R/V BlakeSta. 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 BlakeSta. 117 off Dominica, 15°32′18″N, 061°30′10″W (USNM 1291373), 4 paralectotypesof Drillia pagodulaDall, 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 BlakeStation 273, 1878, off Barbados(MCZ 7069); 1 paralectotypeof D. pagodulaDall, 1889: 14.0 x 5.2 mm, in 154 fms [ 282 m], R/V BlakeStation 282, 1878, off Barbados, (MCZ 7068); 1 paralectotypeof D. pagodulaDall, 1889: 9.6 x 3.8 mm, in 73 fms [ 134 m], R/V BlakeStation 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). 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). Range and habitat. Dominica(offshore); Barbados(offshore); Netherlands Antilles(off SW Curaçao). Reported from 134– 282 m.
Description. Shellmedium (to 26.8 mmin 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. Protoconcheroded on holotype, of 2¼ whorls on juvenile paratype. Lost or eroded on all the other paratypes. Axial sculptureof 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. Varixlarge, convex, wider and much higher than adjacent ribs, but not hump-like. Spiral sculptureof closely-packed heavy raised threads roughened by growth striae. Threads override ribs. Sulcusslightly concave, ribs recurved, just a little lower than on whorl proper. Outer lip“peeled” back to varix by predator on holotypeand the larger paratypes Anal sinusmostly missing on holotype; a deep laterally-directed notch on some paratypes. Inner lipmoderately wide, recumbent, margined, pinched erect anteriorly, and formed into a weak callus posteriorly where it joins the outer lip. Anterior canalmoderately long, open, unnotched; anterior fasciole not swollen. Fasciole sculpture is the same as shell base but spiral threads heavier and wider apart. Colorwhite 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 crassahas 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 ratiois 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. crassais 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.