Gonyostomus elinae, Simone Introduction, 2016

Gonyostomus elinae View in CoL spec. nov.

Figs 1 View Figs 1-6 -7

Type material. Holotype: MZSP 106226 View Materials (sta. LES2205 About LES ) ( Figs 1-4 View Figs 1-6 ) . Paratypes: MZSP 106237 View Materials , 1 View Materials shell from type locality (sta. LES2204 About LES ) ( Fig. 5 View Figs 1-6 ) ; MZSP 104837 View Materials , 2 View Materials shells of uncertain locality (possibly same as the type locality) (sta. LES2068 About LES ) ( Figs 6 View Figs 1-6 -7) .

Type locality. Brazil, São Paulo, Caboclos Region, Iporanga, PETAR ( Alto do Ribeira State Park ), Chapéu Mirim Cave , 24°25'52" S 48°35'07" W ( Bichuette et al. leg., 15.vi.2008) GoogleMaps .

Diagnosis. Shell background colour pale beige to cream, with brownish-purple blotches occupying ~40 % of surface. Sculpture axially elongated, minute nodes arranged in spiral rows (9-10 on penultimate whorl). Aperture wide, with relatively straight inner lip. Umbilicus wide for genus.

Description

Shell ( Figs 1-6 View Figs 1-6 ). Outline fusiform; height about 47 mm, width ~42 % of length; ~5.5 whorls ( Fig. 4 View Figs 1-6 ). Background colour pale beige to cream, with brown to brownish-purple markings, blotches, occupying ~40 % of surface; blotches irregularly arranged in spiral pattern, resulting in 4 equidistant bands on last whorl ( Fig. 2 View Figs 1-6 ). Lower part of body whorl devoid of colour markings; in apertural view ( Figs 1, 5, 6 View Figs 1-6 ) large, light-coloured region, well delimited by distinct, oblique line beginning at junction of columellar and parietal areas, extending downwards, joining white peristome; in dorsal and basal views ( Figs 2-3 View Figs 1-6 , respectively), light-coloured area forming spiral light colour band surrounding umbilicus. Protoconch of 1.5 whorls, rounded profile, with flattened superior surface, weakly carinate in superior region, sculptured by delicate net of axial and spiral lines (Fig. 7), ~10 spiral lines on first whorl; occupying ~15 % of superior shell surface in apical view ( Fig. 4 View Figs 1-6 ); diameter ~ 3.5 mm. Spire acuminate, occupying ~55 % of shell length; spire angle ~35-40 °; suture shallow, whorls weakly convex. Teleoconch sculpture of well-developed growth-lines and axial undulations; surface additionally wrinkled by small, axially elongated nodes on top of undulations, arranged successively in spiral lines, ~9-10 on penultimate whorl ( Fig. 2 View Figs 1-6 ); each node ~3 times as long as wide. Body whorl occupying ~ 2 / 3 of shell length, not more elongated than previous whorls. Aperture completely white, ~twice longer than wide, elliptical; anterior notch well-developed, almost siphon-like, anteriorly directed ( Fig. 3 View Figs 1-6 ); outer lip weakly convex, edge thick, expanded, thereby increasing shell width ~15 %; edge weakly narrower superiorly, gradually becoming wider in inferior portion ( Figs 1, 5, 6 View Figs 1-6 ); edge thinner in anterior notch; superior half of inner lip almost straight, callus thin, translucent ( Figs 1, 5, 6 View Figs 1-6 ), inferior half similar to outer lip, almost straight and with uniform width along its length. Umbilicus relatively wide ( Fig. 3 View Figs 1-6 ), partially covered by expansion of inner lip; possessing shallow spiral marginal furrow.

Measurements (in mm). Holotype: 46.9 by 20.0; MZSP 106237: 46.2 by 20.1; MZSP 104837 #1: 40.9 by 18.4; #2: 36.2 by 15.2 (subadult specimen without expanded peristome).

Habitat. Found dead inside caves, possibly carried in by floods, so, considered accidental in the caves, having come from epigean, possibly arboreal environment.

Distribution. Known only from the type locality.

Etymology. This species is named after Maria Elina Bichuette, Universidade Federal de São Carlos, who is leading a team conducting extensive projects on cave faunas and has donated several mollusc samples resulting in a significant improvement of our knowledge of the Brazilian malacofauna.