Bellaspira minutissima, 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 : 35-36

Bellaspira minutissima , new species

( Plate 10 )

Type material. Holotype 5.4 x 2.2 mm (ANSP 368731); 1 paratype: 4.7 x 2.0 3.2 mm, in 460 m, Memory Rock, Grand Bahama I., 26°57′00"N, 079°06′00"W (ANSP 368185). Both types B. Rose! ex J. Worsfold coll.

Type locality. West End, Grand Bahama I., Bahama Is., 26°42'15''N, 078°59'50''W, in 305 m.

Range and habitat. Off Grand Bahama I.; reported from bathyal depths of 305– 460 m.

Description. Shell very small (to 5.4 mm total length), short, rather stout, truncated anteriorly, surface glossy; with a total of 5½ moderately convex whorls, spire short, last whorl disproportionately large, approximately 66% of total shell length; sculpture of ribs; aperture oval. Protoconch of 1¾ smooth whorls, the first partially immersed in the second so that the shell appears to be dome-shaped. Axial sculpture of ribs that run from suture-to-suture on spire whorls, evanesce below periphery on last; number 10 on penultimate, 9 on last, are little changed on shoulder, crests round; intercostal spaces a little wider to about the same as rib width. Varix a swollen rib a little distance from the outer lip’s edge. Spiral sculpture of very fine grooves that become ridge-like and deeper anteriorly, made wavy by growth striae; spiral groves present on anterior fasciole. Sulcus absent; lower, narrower, and very slightly curved ribs on whorl shoulder mark former positions of the anal sinus. Outer lip thin, a very shallow indentation at the anal sinus; without a stromboid notch. Anal sinus formed as a weak indentation on outer lip; no significant callus visible on the parietal or inner surface of outer lip. Inner lip recumbent, margined, thin on parietal wall, thickest anteriorly. Anterior canal short, open, turned slightly to the left when viewed ventrally, with a slight notch. Color white.

Remarks. Taxonomy. Bellaspira minutissima is like other members of Bellaspira in possessing the characteristic spiral groove microsculpture, ribs that run suture-to-suture, little changed in the sulcal area, and in lacking a notched anal sinus. Identification. Bellaspira . minutissima is closest in size but smaller than B. hannyae (Jong & Coomans, 1988) (total length to 5.4 versus to 7.8 mm). Bellaspira minutissima is similar in profile to B. pentagonalis (Dall, 1889) , B. amplicostata , new species, and B. aurantiaca , new species but is smaller, has more axial ribs, and lacks color, which is present in the other three. Bellaspira minutissima has 10 ribs on the penultimate whorl, B. pentagonalis has 5, B. amplicostata has 7–8, and narrower ribs, and B. aurantiaca has 5–8 ribs on the penultimate whorl. These distinctive differences, and the its geographic isolation as the only described species of Bellaspira from the Bahama islands, merit its description.

Etymology. The Tiniest Bellaspira , from the Latin adjective minutissimus, feminine minutissima , meaning the tiniest.

Figures

PLATE 10 Bellaspira minutissima, new species. Figs. 1 – 2: holotype, West End, Grand Bahama I., Bahama Is. (ANSP 368731). Fig. 1: ventral, lateral & dorsal views; Fig. 2: apical view, V = varix, L = edge of lip. Fig. 3: paratype, Memory Rock, Grand Bahama I. (ANSP 368185).