Eocithara, Fischer, 1883

Merle, Didier & Pacaud, Jean-Michel, 2004, New species of Eocithara Fischer, 1883 (Mollusca, Gastropoda, Harpidae) from the Early Paleogene with phylogenetic analysis of the Harpidae, Geodiversitas 26 (1), pp. 61-87 : 69-70

Eocithara (s.s.) eucosmia n. sp. ( Figs 4G, H ; 5 A-C; 6F)

TYPE MATERIAL. — Holotype ( MNHN R 63798, Boucher coll.), Bois-Gouët; 2 paratypes ( MNHN R 63434 and MNHN R 63435, Pacaud coll.), 1 paratype ( MNHN R 63797, Faullummel coll.), Bois- Gouët; 1 paratype ( MNHN R 11404, Ledon coll.), Saint-Aignan-de-Grand-Lieu.

TYPE LOCALITY. — Bois-Gouët, Saffré, Loire-Atlantique, France, Bartonian.

ETYMOLOGY. — From the Greek: well organized.

MEASUREMENTS. — R 63798 (holotype): height 32 mm, maximal width 19 mm ; R 63434 (paratype): height 10 mm, maximal width 4.5 mm (aperture broken) ; R 63435 (paratype): height 7 mm (apex broken), maximal width 3 mm (aperture broken) .

DESCRIPTION OF THE HOLOTYPE

Shell 32 mm in height and 19 mm in width, weakly inflated. Protoconch eroded, of one large whorl. Teleoconch of 5.25 weakly convex whorls. Conical spire 17% of total length. Suture simple, linear. Axial sculpture of sigmoid, lamellose, and abaxialy oriented major varices. Posterior part of each major varix adapically projected and moderately covering base of penultimate whorl. Fourty-five major varices on first whorl, 31-32 equally spaced major varices on third and 11 on last whorl. Eleven to 14 very lamellose secondary varices between each pair of major varices on last whorl. Spiral cords lacking on the first whorl, but appearing on second whorl as four narrow cords (P1 to P4). P1 delineating a small carina on third whorl, but not on last whorl. Secondary cord appearing on third whorl. Primary and secondary cords indistinguishable on last whorl. Cord spine P1 absent, but only a small angle on the whorl. Axial microsculpture faint. Oblong aperture of 75% of total length, contracted in its abapical angle. Centre of columella straight, lightly curved in anterior part. Columellar callosity slightly expanded in parietal area and well delineated in its labial part. Pseudoumbilicus narrow, closed by columellar callosity and delineated by umbilical ridge. Umbilical ridge curved dorsally. Siphonal canal short, curved dorsally. Outer lip thin, but thickened by the last varix, orthocline, with parasigmoid outline.

COMPARISONS

This new Bartonian species is known by five specimens from Bois-Gouët and Saint-Aignan-de- Grand-Lieu. They have the same sculpture at the two localities. On the first whorl, it is characterized by very sinuous varices and by lacking spiral cords. This sculpture represents a previously unknown character in Eocithara , as all other species have spiral cords. Moreover, the number of varices on the first (45) and the second (31-32) whorls is much higher than in the other European species. It also has more numerous and more lamellose secondary varices (12-14) than in E. (s.s.) helenae n. sp. (5-6) and in E. (s.s.) mutica (4-10).

Figures

FIG. 4. — A, B, Eocithara (s.s.) mutica (Lamarck, 1803), MNHN R63429 (Schtrock coll.), Chaussy, Val d’Oise, France, Lutetian; C, D, E. (s.s.) mutica, MNHN R63430 (Leroy coll.), Saint-Gobain, Aisne, France, lower Ypresian; E, F, E. (s.s.) helenae n. sp., holotype, MNHN R63431 (Merle coll.), Tuilerie of Gan, Pyrénées-Atlantiques, France, upper Ypresian; G, H, Eocithara (s.s.) eucosmia n. sp., holotype, MNHN R63798 (Boucher coll.), Bois-Gouët, Saffré, Loire-Atlantique, France, Bartonian. Scale bars: 10 mm.

FIG. 5. — A-C, Eocithara (s.s.) eucosmia n. sp., paratypes, MNHN R63434 et R63435 (Pacaud coll.), Bois-Gouët, Saffré, Loire- Atlantique, France, Bartonian; D-E, E. (s.s.) rosenkrantzi n. sp., holotype, MGUH 15818 (copy MNHN R63692), Sonja Lens, East of Turritellakløft, Nuussuaq Peninsula, West Greenland, Thanetian (Agatdal Formation); F, E. (s.s.) sp. 1, MNHN J05430 (Cossmann coll.), Coustouge, Aude, France, lower Ypresian; G-H, Eocithara (s.s.) sp. 2, MNHN R63432 and R63433 (Courtessolle-Griffe coll.), Les Capitelles, North of Aragon, Aude, France, lower Ypresian. Scale bars: A-E, 5 mm; F-H, 10 mm.