Leptadrillia loria 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 : 223-224

Leptadrillia loria Bartsch, 1934

( Plate 110 )

Leptodrillia [sic] loria Bartsch, 1934: 25 , pl. 7, figs. 1, 3, 4. Powell (1966: 91).

Unconfirmed fossil reports:

Leptadrillia loria Bartsch, 1934 : Perrilliat (1973: 53, pl. 25, figs. 3–6).

Type material. Holotype 6.8 x 2.3 mm (USNM 430701).

Type locality. R/V Caroline Sta. 106, off the N coast of Puerto Rico, between 18°3l'20"N, 66°16'30"W, and 18°31'30"N, 66°18'20"W, in 150–195 fms [274–357 m].

Range. Known only from the holotype. Reported from 274– 357 m.

Description. Shell very small (6.8 mm), narrowly fusiform (W/L = 0.338), glossy, translucent; whorls convex, number to 8½, the last approximately 60% of the total length; axial sculpture predominant; aperture narrow; anterior canal moderately long. Protoconch of 1½–1¾ smooth, translucent whorls, first expands rapidly such that the apex is lopsided. Axial sculpture of slightly curved, narrow ribs that run from suture-to-suture, 10 on the penultimate, 10 the body whorl to the varix, peripheries below mid-whorl that are recurved in the sulcus, and sigmoid last whorl where they end at the anterior fasciole; crests round, not ridged. Ribs on first teleoconch whorl angular, almost knob-like. Rib interspaces vary ½–2 time the width of ribs. Growth striae faint, cross ribs diagonally and recurved on whorl shoulder. Varix rib-like but straighter, larger, not curved at twice the width of previous ribs, positioned well behind the anal sinus, about ¼–⅓-turn from the edge of the outer lip. Spiral sculpture is absent except for spiral threads on the anterior fasciole. Sulcus obscure but marked by lower, recurved ribs and curved growth striae. Outer lip thin, translucent, occasionally strengthened by clusters of heavy growth striae or weak folds. Swelling along suture of outer lip indicate previous positions of the parietal lobe. Lip edge forms an arc from and congruent with anal sinus to the stromboid notch; edge of lip bends in toward aperture and outward at anal sinus. Stromboid notch shallow. Anal sinus deep, U-shaped; entrance not constricted by parietal callus; callus and laterally directed sinus cause the sinus to appear spout-like. Inner lip recumbent, emarginated except on parietal wall; knob-like posteriorly forming parietal side of anal sinus, erect along anterior canal. Anterior canal is moderately long, turned slightly to the right when viewed ventrally; fasciole not swollen, with 6– 8 spiral threads; tip of canal very slightly notched. Color translucent white, ribs more opaque.

Remarks. Taxonomy. Leptadrillia loria closely matches the characteristics established by Woodring for the genus. Shells are spindle-shaped with a long anterior canal, ribs suture-to-suture, recurved on the shoulder, and shell surface smooth, except for spiral threads on the anterior canal. Identification. Bartsch roughly characterized L. loria as a small L. splendida . The holotype is 6.8 mm compared to the 9.2 mm length of the holotype of L. splendida . While they appear very similar in form, the anterior canal of L. loria is shorter in proportion to the rest of its shell than that of L. splendida , and the protoconch of L. loria is smaller. Leptadrillia loria is also similar to Syntomodrillia socolatea , new species, S. triangulos , new species and S. mellea , new species. From S. socolatea it differs in having a longer anterior canal, sigmoid ribs on the last whorl, not slightly opisthocline ribs, whorl peripheries closer to mid-whorl, a more streamlined body, and an all-white, not a light golden to chocolate brown color. From S. triangulos it differs in having a longer, more curved anterior canal, and a more streamlined shell, and lacking faint spirals between ribs on the last whorl. From S. mellea it differs in having a longer, more curved anterior canal, a slimmer shell, lacking faint spirals between ribs on the last whorl, and a different color—white, not light golden brown with whitish shell base and varix.

Figures

PLATE 110. Leptadrillia loria Bartsch, 1934. Figs. 1 – 3: holotype, off the N coast of Puerto Rico (USNM 430701). 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.