Leptadrillia moorei, 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 : 228-229

Leptadrillia moorei , new species

( Plate 114 )

Type material. Holotype 10.0 x 3.2 mm, J. Moore! 1963, ex. Germer coll. (AMNH 311992); 4 paratypes, all from the holotype lot: 8.8 x 2.8, 6.0, 7.0, 6.8 (AMNH ICZ 249989).

Type locality. West of Bayport, Hernando County, W Florida, in 46 m.

Other material examined. An additional two specimens were examined that may be this species: 8.1 x 2.8 & 9.7 x 3.3 mm, from the type lot (AMNH ICZ 249990).

Range and habitat. Known only from the type locality.

Description. Shell very small (to 10.0 mm in total length), glossy, narrowly fusiform; early whorls convex but last 2–3 spire whorls flat sided with deeply impressed sutures; whorls number up to 9¾, the last about 55% of total length; aperture narrow and anterior canal long. Surface of shell sculpted by regularly spaced axial ribs, widest at whorl periphery and slightly recurved on shoulder. Protoconch of approximately 2 smooth, round translucent whorls, the first partially immersed in the second such that the whole appears bulbous. Axial sculpture of narrow, straight ribs on spire whorls, somewhat sigmoidal on last; ribs with ridged crests that run from suture-to-suture on spire whorls, to anterior fasciole on last; ribs wider to as wide as their intercostal spaces. Ribs deeply impressed at suture. Varix large and protruding, wider than preceding ribs, straight not sigmoidal, and round-crested; positioned approximately ¼-turn from lip edge. Spiral sculpture absent except for the presence of spiral threads on anterior fasciole. Sulcus absent. Outer lip absent to varix, probably chipped away by predators. Anal sinus also missing on types. Inner lip narrow, margined, formed into a parietal callus posteriorly at the anal sinus. Anterior canal long, open, and straight; unnotched. Color translucent white; ribs opaque white.

Remarks. Taxonomy. Leptadrillia moorei has all of the distinguishing characteristics of Leptadrillia : a glossy, spindle-shaped shell with a narrow aperture and long anterior canal, ribs that extend from suture-to-suture, and spiral sculpture absent except for the presence of threads on the anterior fasciole. Variability. The average total length of 7 specimens is 8.06 mm (6.0–10.0 mm), and their average W/ L ratio is 0.331. Identification. Leptadrillia moorei is similar to the following five species: L. splendida Bartsch, 1934 , L. violacea , new species, L. histriata , new species, L. lizae , new species, and L. profunda , new species. From L. splendida it differs in having less convex whorls. L. moorei has nearly flat whorls like both L. histriata and L. violacea , but these two species are a different color, L. violacea a pale violet and L. histriata a light beige, and especially for the latter species, possessing more numerous ribs. From L. lizae it differs in being narrower (average W/ L ratio = 0.331 versus 0.346) and its whorls are less convex. Similarly, it is narrower than L. profunda (average W/ L ratio = 0.355) and has a longer anterior canal.

Etymology. Jim Moore’s Leptadrillia . Named in honor of Jim Moore who dredged throughout the Gulf of Mexico for rare offshore species, including all of the specimens listed here.

Figures

PLATE 114. Leptadrillia moorei, new species. Figs. 1 – 2: holotype, west of Bayport, Hernando Co., W Florida (AMNH 311992). Fig. 1: ventral, lateral & dorsal views; Fig. 2: apical view, V = varix, L = edge of outer lip; Figs. 3 – 6: paratypes from the type locality, ventral views, all in AMNH ICZ 249989. Fig. 5: ventral & dorsal views.