Leptadrillia splendida Bartsch, 1934

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 : 231-232

Leptadrillia splendida Bartsch, 1934

( Plate 116 )

Leptodrillia [sic] splendida Bartsch, 1934: 24 , pl. 7, figs. 2, 5, 7.

Cerodrillia simpsoni (auct. non Dall, 1887) is a misidentification by Nowell-Usticke (1959: 81–82, pl. 4, fig. 10).

Leptadrillia splendida Bartsch, 1934 : Powell (1966: pl. 14, fig. 14); Kaicher (1984c: card 3904); Turgeon et al. (1988); Williams (2005, 2006, 2009: species “+1575” [not synonymy with L. cookei ]).

Cymatosyrinx (Leptadrillia) splendida (Bartsch, 1934) : Abbott (1974: 276, specimen no. 3119).

Leptadrillia cookei auct. non (E.A. Smith, 1888): Jong & Coomans (1988: 113 [incorrectly synonymize L. splendida with L. cookei ]). Williams (2005: species 1575 [left photo of holotype only]); Williams (2006: species 1575 [left photo of holotype only; right photo =undescribed Brazilian species]).

Not this species or unconfirmed extralimital reports.

Leptadrillia splendida Bartsch, 1934 : Warmke & Abbott (1961: 136, pl. 25, fig. j [ Puerto Rico]); Rice & Kornicker (1965: 126, pl. 7, fig 1 [Campeche Bank]); Houbrick (1968: 17 [ Costa Rica]); Rios (1970 [ Brazil]); Ekdale (1974: 650 [Quintana Roo, Mexico]); Rios (1975: 134, pl. 40, fig. 607 [fig. not clear]); Rios (1985: 140, pl. 48, fig. 649 [ Brazil]); Rios (1994: 161, pl. 53, fig. 722 [ Brazil]); Díaz (1994 [ Colombia]); Diaz & Puyana (1994: 224, pl. 67, fig. 886 [fig. of Colombian specimen not clear]); Absalão et al. (2005: 24, fig. 18 [fig. of Brazilian specimen not clear]); Daccarett & Bossio (2011: 130, fig. 796 [ Colombia]).

Cymatosyrinx splendida (Bartsch, 1934) : Sander & Lalli (1982: 317 [ Barbados = Leptadrillia violacea , new species]).

Type material. Holotype 9.2 x 3.1 mm (USNM 429368).

Type locality. R/V Caroline Sta. 56, Samaná Bay, [ Dominican Republic], between 19°10'15"N, 69°27'20"W and 19°10'15"N, 69°28'05"W, in 17 fms [31 m].

Other material examined. Three additional specimens were examined: 9.0 x 3.0, 8.1 x 2.8 & 7.5 x 2.5 mm, Altona Bay, St. Croix, U.S. Virgin Is., May 1958, ex coll. G. Nowell-Usticke (AMNH 192601, in part).

Range and habitat. Dominican Republic; U.S. Virgin Is. (St. Croix). The holotype was taken from a depth of 31 m.

Description. Shell very small (to 9.2 mm in total length), glossy and translucent, narrowly fusiform; whorls moderately convex with peripheries below mid-whorl, up to 8¾ whorls, last approximately 57% of total length including canal; axial ribs are sculptural element; aperture moderately wide, long. Protoconch of 1½–2 evenly expanding, smooth, glossy whorls, the first only a little smaller in diameter than the second. Axial sculpture of sigmoid ribs that run from suture-to-suture, highest, widest, and inflected near whorl midpoint; low, narrow, and curved in sulcus such that the leading face is concave; evanesce at anterior fasciole on last whorl, except mostly obsolete on parietal wall. Ribs on first three teleoconch whorls knob-like then lengthen on subsequent whorls; ribs number 8–10 on penultimate and 6–8 to the varix on last whorl. Very fine, microscopic growth striae present throughout. Varix runs from suture to anterior fasciole, gradually diminishing anteriorly; larger than and 2–3 times the width of the preceding ribs; positioned about ¼–⅓-turn from the edge of the outer lip. Spiral sculpture absent, except for approximately 9 spiral threads on the anterior fasciole. Sulcus obscure, marked by lower, narrower ribs curved to reflect the outline of the anal sinus. Outer lip mostly missing on type specimen. Anal sinus missing on type specimen. Inner lip thin, recumbent, margined, thicker anteriorly along anterior canal, posteriorly forms a weak parietal lobe. Anterior canal long, straight, open, anterior end turned very slightly to the right when viewed ventrally; end unnotched. Color white, outer lip, and rib interspaces translucent.

Remarks. Taxonomy. Leptadrillia splendida has all the important characteristics of the genus: a narrow, spindly shell with a long anterior canal, narrow ribs that extend from suture-to-suture, and the absence of spiral sculpture, except for threads or ridges on the anterior fasciole. Variability. The four examined specimens have an average total length of 8.45 mm (7.5–9.2 mm) and an average W/ L ratio of 0.337. Identification. Leptadrillia splendida is may be confused with some of its congeners: L. campechensis , new species, L. lizae , new species, L. loria Bartsch, 1934 , L. profunda , and L. histriata , new species. Leptadrillia campechensis is very similar but has slightly more convex whorls, taller spire, and more oblique ribs. It also has a more convex last whorl. From L. lizae it differs in having more oblique ribs, and a longer anterior canal. From L. loria it differs in being larger (total length is 9.2 mm versus 6.8 mm) and having a proportionately longer anterior canal and larger protoconch. From L. profunda it differs in possessing more angular whorls with peripheries more anterior to whorl midpoints, and a longer anterior canal. From L. histriata it differs in possessing fewer ribs (up to 10 versus 13–15 on the penultimate whorl), and round-crested ribs, not ridged ones.

Figures

PLATE 116. Leptadrillia splendida, Bartsch, 1934. Figs. 1 – 3: holotype, Samaná Bay, Dominican Republic (USNM 429368). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged view of protoconch (not to scale); Fig. 3: apical view, V = varix, L = edge of outer lip. Figs. 4 – 6: Altona Bay, St. Croix, U. S. Virgin Is., ventral views (AMNH 192601).