Pseudosubulina theoripkeni, Gargominy & Muratov, 2012

Gargominy, Olivier & Muratov, Igor V., 2012, New taxa of land snails from French Guiana, Zoosystema 34 (4), pp. 783-792 : 786-789

Pseudosubulina theoripkeni n. sp. ( Figs 3 ; 4 )

Pseudosubulina sp. – Massemin et al. 2009: 417, pl. 9K, 420 (same specimen as Fig. 3D ; dissected paratype MNHN 25069 ).

TYPE MATERIAL. — Holotype: French Guiana, Réserve naturelle des Nouragues, Nouragues field station (c. 4°05’N, 52°41’W; G17 square), 75 m a.s.l., rec. T. E. J. Ripken & O. Gargominy, 03.XI.1997, under leaf litter near stream at thebaseofgraniticrock( INVMAR21004 ), MNHN 25068 . Paratypes:samedataasholotype, 2 specimens, MNHN 25069 (dissected) and 25070.— Same data, but M12 square, 140 m a.s.l., 08.XI.1997, leaflitteronlateriticsoil ( INVMAR21021 ), 5 specimens, MNHN 25071 . — Same data, but N15 square, 155 m a.s.l., T. E. J. Ripken & O. Gargominy, 15.XI.1997, leaf litter on lateritic soil in buttresses of tree (tree code N-15-138) ( INVMAR21038 ) MNHN 25072 .

OTHER MATERIAL EXAMINED. — Same data as holotype, 3 damaged shells ( MNHN). — Same data, but N10 square, 140 m a.s.l., 11.XI.1997, leaf litter on lateritic soil in a natural forest gap ( INVMAR 21029), 7 damaged shells ( MNHN). — Road to Cacao, 4.56548°N, 52.41922°W, 23.X.1997, T. E. J. Ripken & O. Gargominy, on a burnand-slash stand ( INVAR 20978), 1 old shell ( MNHN).

TYPE LOCALITY. — Nouragues field station (c. 4°05’N, 52°41’W), Réserve naturelle des Nouragues, French Guiana.

ETYMOLOGY. — This species is dedicated to Theo E.J.Ripken, eminent conchologist, sparkling teacher, friend from the French Guiana field trips and co-discoverer of this species.

DIAGNOSIS. — Shell narrowly umbilicate, slender, turrited with straight outline and obtuse apex; consists of up to 14 evenly rounded, tightly coiled whorls with a deep straight crenulated suture. Protoconch glossy with faint radial and spiral sculpture. Surface of teleoconch with strong radial ribs, well defined on early whorls and slightly narrower than intercostal spaces,gradually disappearing below periphery on later whorls.Penis as long as free oviduct, internally with large stimulator and opposing pilaster inside its proximal part.

DESCRIPTION (HOLOTYPE)

Shell of normal size for the genus (height 13.3 mm, major diameter 2.9 mm), narrowly umbilicate,dextral, slender, turrited with straight outline, rather thin, semi-translucent, pale corneous.Whorls 13.7, evenly rounded with a deep straight crenulated suture all the way to the aperture. Protoconch 2+ whorls, glossy with faint radial and spiral sculpture. Protoconch/ teleoconch transition distinct because of change in macrosculpture. Surface of teleoconch with strong radial ribs, well defined on early whorls and slightly narrower than intercostal spaces,gradually disappearing below periphery on later whorls.Growth lines visible only just before the aperture. Aperture elongated, orthocline, with approximately 90° columellar-basal angle, cut by penultimate whorl, with whitish parietal callus. Peristome simple, with sharp margin, not reflected except at columellar edge; reflection of columellar edge more developed in its upper part. Umbilicus tiny, not covered by columellar edge.

Body white (see illustrated live specimen [paratype

MNHN 25069] in Massemin et al. [2009: 420]).

ANATOMY (PARATYPE MNHN 25069)

Jaw thin, arcuated, vertically striated. Free oviduct long and thickened.Vagina very short.Uterus contains several embryos.Spermatheca with medium-sized oval reservoir and long duct.Penis as long as free oviduct, internally with large stimulator and opposing pilaster inside its proximal part.Vas deferens long, thin, enters penis apically through base of penial retractor and opens into long deep furrow on side of stimulator.

HABITAT. — Primary forest, under leaf litter on granitic or lateritic soil.

REMARKS

The description of P. theoripkeni n. sp. extends not only our knowledge of the geographical distribution of the genus Pseudosubulina (previously known with certainty from Mexico only) but also the diagnosis of the genus.Our knowledge of the anatomy of this genus is still very limited but it is evident now that internal penial structures vary from three main opposing penial pilasters in the type species ( P.berendti ; see Baker1939) to the stimulator and the opposing single pilaster in P. theoripkeni n. sp. This opposing functional pair is already present in the penis of P. berendti and has been further enhanced in P. theoripkeni n. sp.

Figures

FIG. 3. — Pseudosubulina theoripkeni n. sp.: A-C, holotype MNHN 25068; B, details of teleoconch sculpture; C, details of collumelar surface sculpture; D, paratype MNHN 25069 used for dissection. Scale bars: A, D, 5 mm; B, C, 0.5 mm.

FIG. 4. — Anatomy of Pseudosubulina theoripkeni n. sp., paratype MNHN 25069: A, distal genitalia; B, internal structure of penis. Abbreviations: E, one of the embryos; P, penis; S, spermatheca; VD, vas deferens. Scale bars: A, 1 mm; B, 0,5 mm.