Inella numerosa Jousseaume, 1898

Albano, Paolo G., Franco, Davide Di, Azzarone, Michele, J., Piet A., Bakker & Sabelli, Bruno, 2023, Review of the types of Indo-Pacific Triphoridae (Mollusca, Gastropoda) in the Muséum national d’Histoire naturelle, Paris, Zoosystema 45 (2), pp. 13-106 : 85-86

Inella numerosa Jousseaume, 1898

( Fig. 57 )

Inella numerosa Jousseaume, 1898: 72 , not illustrated.

TYPE LOCALITY. — Perim Island, Bab al-Mandab Strait, Yemen.

ADDITIONAL ORIGINAL LOCALITIES. — Jeddah, Aden, Djibouti.

TYPE MATERIAL. — Lectotype • MNHN-IM-2000-29264; here designated.

Paralectotypes. Triphoridae indet. Yemen •MNHN-IM-2000-509; 11 specimens; Perim Island , Bab al-Mandab Strait, Yemen .

ORIGINAL DESCRIPTION. — Testa solida, ovato-cylindrica, apice subulata , nigricante-fulva, costis granulosis tribus cincta, granula opposita in seriebus longitudinalibus disposita; anfr. 13 primi laeves, sequentes granuloso-cancellati, ultimus antice rotundatus, carinis moniliformibus quinque rugatus; sutura profunda canaliculata; apertura rotundata lateraliter fissa; canalis brevis parum recurvus. Long. 3mm 5; diam. 1mm. [Latin diagnosis followed by a discussion in French]

TRANSLATION OF THE LATIN TEXT. — Solid shell, cylindrical-ovate, subulate apex, dark brown, with three granular spiral cords, granules are arranged in longitudinal series; 13 whorls, first ones smooth, subsequent whorls granulated-cancellated, last whorl rounded, with five tubercled spiral cords; deep and canaliculated suture; rounded and laterally fissured aperture; short and slightly curved siphon. Length 3.5 mm; diameter 1 mm.

DIAGNOSIS. — Shell cyrtoconoid with flat sides. Lectotype 4.2 mm high. Teleoconch of 8 whorls. Three spiral cords present starting from the first teleoconch whorl. All three cords with tubercles at the intersection with rather orthocline axial ribs. Peristome without additional cords. Posterior sinus barely visible in the lectotype. Base with three additional tubercled cords. Multispiral protoconch of four whorls with one keel and equally strong axial riblets. Teleoconch and protoconch brown.

REMARKS. — The lot in the collection contained 12 specimens belonging to at least two, if not more, species belonging to a difficult group of small-sized and uniformly coloured (usually brown) taxa. The main difference among the specimens is that four specimens ( Fig. 56 A-J, V-X) have three spiral cords since the beginning of the teleoconch, whereas the others have the second cord developing later, usually in the second half of the teleoconch. Jousseaume (1898) wrote that “ Inella ” numerosa is characterized by three tubercled spiral cords (“ costis granulosis tribus cincta ”) and brown colour (“ nigricante-fulva ”); both characters are visible only in a single specimen of the original series, which is here designated as lectotype to stabilize nomenclature. The generic assignment is also dubious, but we refrain from further comments pending a full revision of triphorid genera.

Figures

FIG. 57. — Inella numerosa Jousseaume, 1898, Perim Island, Bab al-Mandab Strait,Yemen: A-J, lectotype, MNHN-IM-2000-29264: front (A, B), side (C, D), back (E), peristome (F, G), microsculpture (H), protoconch (I, J); K-U, Triphoridae indet. (non Inella numerosa), Perim Island, Bab al-Mandab Strait, Yemen, MNHN- IM-2000-509: protoconch (K, L), front (M, N), side (O, P), back (Q), first protoconch whorl (R), microsculpture (S), peristome (T-U); V, Triphoridae indet. (non Inella numerosa), Perim Island, Bab al-Mandab Strait, Yemen,paralectotype,MNHN-IM-2000-509: front; W, Triphoridae indet. (non Inella numerosa), Perim Island,Bab al-Mandab Strait,Yemen,paralectotype,MNHN-IM-2000-509: front;X, Triphoridae indet.(Inella numerosa?), Perim Island,Bab al-Mandab Strait,Yemen,paralectotype, MNHN-IM-2000-509: front; Y-Z, original labels lot MNHN-IM-2000-509. Scale bars: A-E, M-Q, V-X, 1 mm; F, G, T-U, 0.4 mm; H-L, S, 0.2 mm; R, 0.1 mm.

FIG. 56. — Obesula mus Jousseaume, 1898, Djibouti: A-I, syntype, MNHN-IM-2000-1595 front (A, B), side (C, D), back (E), protoconch (F, G), peristome (H), microsculpture (I); J-L, original labels. Scale bars: A-E, 1 mm; F, G, 0.1 mm; H, 0.5 mm; I, 0.2 mm.