Lanayrella ringei ( Strebel, 1905 ) Salvador & Cunha, 2020

Salvador, Rodrigo B. & Cunha, Carlo, 2020, Lanayrella, a new Acteonidae genus (Gastropoda, Heterobranchia) from Tierra del Fuego, Journal of Natural History 54 (15 - 16), pp. 1009-1018 : 1015-1016

Lanayrella ringei ( Strebel, 1905) comb. nov. ( Figure 2 )

Actaeon ringei Strebel, 1905: 576–577 , pl. 22, figs 31, 31a–b.

Type locality

Argentina: Tierra del Fuego, Strait Le Maire.

Type material

Syntypes ZHM 12833 (3 shells) .

Diagnosis

Whorls and spire proportionately shorter than L. vagabunda ; shell wall thicker; aperture less elongated. Teleoconch sculptured by less numerous punctate spiral grooves, more widely space than L. vagabunda ; punctae rectangular, large and well defined only on first whorls, becoming more elongated and less defined individually on later whorls.

Redescription

Shell thick, elongated, last whorl with a slightly rounded profile, imperforate; D/H 0.49. Spire short, with slightly rounded whorls and faintly step-like profile; suture distinctly marked. Colour light brown. Protoconch indistinct, nucleus fully immersed ( Figure 2 (h)); first whorl width 0.34 mm. Teleoconch with 4.5 whorls, entirely sculptured by narrow punctuated spiral grooves (~20 grooves on last whorl), separated from each other by a distance of unsculptured shell of twice to thrice the width of each groove (0.09 mm); grooves become more numerous in later whorls and more closely packed together towards umbilicus ( Figure 2 (c)). Grooves composed initially of small roundedrectangular punctae on first whorls, partially fused to the next one within each groove but still individually distinct ( Figure 2 (c)). On later whorls, punctae become narrower and more fused with their neighbours, becoming less distinct individually; the groove takes the appearance of an almost continuous furrow ( Figure 2 (g)). Aperture anteriorly rounded, lightly narrowed posteriorly; h/H 0.58; parietal region 0.5 h, with thin welldelimited callus; columellar region broad, slightly expanded, with a sharp edge, bearing a thickened adapical fold; outer lip sharp, thickened externally.

Measurements

Syntype #1, H = 8.0 mm, D = 4.2 mm, S = 3.2 mm, h = 4.8 mm, d = 2.1 mm. Syntype #2, H = 7.7 mm, D = 4.0 mm, S = 3.3 mm, h = 4.4 mm, d = 1.8 mm. Syntype #3 (fragmentary), H = 7.1 mm, D = 3.5 mm, S = 3.0 mm, h = 4.1 mm, d = 1.6 mm.

Distribution

Tierra del Fuego, Strait Le Mare. Further occurrences and bathymetric range uncertain due to species being long considered synonymous with L. vagabunda .

Figures

Figure 2. Lanayrella ringei, syntypes; spm #1: H = 8.0 mm; spm #2: H = 7.7 mm. A. Spm #1, apertural view. B. Spm #1, dorsal view. C. Spm #1, apertural view, under SEM. D. Spm #2, apertural view. E. Spm #1, detail of spire top showing teleoconch sculpture. F. Spm #1, apical view, under SEM. G. Spm #1, detail of body whorl showing teleoconch sculpture under SEM. H. Spm #1, detail of spire top, under SEM, showing fully immersed protoconch. Scale bar = 200 μm.