Seraphs leukoleptus Jung, 1974

Caze, Bruno, Merle, Didier, Pacaud, Jean-Michel & Saint Martin, Jean-Paul, 2010, First Systematic Study using the Variability of the Residual Colour Patterns: The Case of the Paleogene Seraphsidae (Mollusca, Gastropoda, Stromboidea), Geodiversitas 32 (3), pp. 417-477 : 438

Seraphs leukoleptus Jung, 1974 ( Figs 11 F-I; 13)

Seraphs leukoleptus Jung, 1974: 23 , 24, pl. 6, figs 1-3, text-fig. 17.

Terebellum (Seraphs) fusiformopse – Cossmann 1889: 97, pl. 3, figs 3, 4; 1904: 46 partim. — Cossmann & Pissarro 1911: pl. 31, fig. 158-3. Non Terebellum fusiformopse de Gregorio, 1880 .

Seraphs leukoleptus – Le Renard 1992: 6. — Le Renard & Pacaud 1995: 112. — Pacaud & Le Renard 1995: 162.

Type locality. — Chaussy, Les Garennes (Val d’Oise, France), Lutetian (Middle Eocene).

TYPE MATERIAL. — Holotype (Deshayes coll.); 1 paratype (Deshayes coll., Les Garennes, Chaussy). Unfortunately, the type material of this species has not been found in the Deshayes collection, deposited at the UCBL. A neotype designation is needed to clarify the taxonomic status of this species. A neotype from the type locality ( MNHN A28781, Ledon leg.; Figs 11F, H, I ; 13 A-D) is thus chosen here. Th is initiative conforms to the rules specified by the ICZN (1999: art. 75), as regards the designation of a neotype.

OTHER MATERIAL EXAMINED. — See Appendix 1.

DESCRIPTION

Shell

Shell up to 36 mm in height and 8 mm in diameter, very slender and elongated, with straight and almost parallel sides ( Fig.11F, H ). Aperture long and narrow. Callus of the inner lip very thin, but well delineated, continuing adapically on the spire and forming a narrow band parallel to the outer lip. Columella slightly bent backwards near the base. Outer lip thickened, almost straight in labral view,opisthocline and extending to the apex ( Fig. 11I ). Shallow siphonal notch on the dorsal side of the shell ( Fig. 11H ). Few oblique faint grooves near the base ( Fig. 11G ).

Colour pattern

The residual pattern is only composed of 2 levels of residual pigmentation: dark dots on a lighter background ( Fig. 13 ). Th e dark dots are small and spirally elongated forming narrow triangles ( Fig. 13 B-C, I). These triangles, orientated towards the outer lip, are irregularly spread over the whole surface.

COMPARISONS

Seraphs leukoleptus is the only species having a shell with straight and almost parallel sides. Moreover, it is easily distinguished from the other species by a shallow siphonal notch. Th e pattern of S. leukoleptus is distinguishable from the other patterns by its dots. Th ey do not form rows, as observed in S. volutatus and S. olivaceus . Moreover, these dots are composed of only one level of residual pigmentation, while the other species have dots composed of two levels of residual pigmentation.

Figures

FIG. 11.— Seraphs Montfort,1810 shells in normal light:A-C, Seraphs sp.1, MNHN A25011 (Faullummel coll.),Chaussy (Les Garennes), Val d’Oise, France, Lutetian; A, ventral view; B, labral view; C, dorsal view; D, E, Seraphs sp. 2, MNHN A28887 (de Morgan coll.), Fresville (Coteau de Vauville), Manche, France, Lutetian; D, labral view; E, dorsal view; F-I, S. leukoleptus Jung, 1974; F, H, I, neotype, MNHN A28781 (Ledon leg.), Chaussy (Les Garennes), Lutetian; F, ventral view; H, dorsal view; I, labral view; G, MNHN A28968 (Houdas coll.), Chaussy, Lutetian, detailed view of the oblique grooves. Scale bars: A-F, H, I, 10 mm; G, 5 mm. Photographs by C. Lemzaouda (MNHN).

FIG. 13. — Seraphs leukoleptus Jung, 1974, under UV light: A-C, neotype, MNHN A28781 (Ledon leg.), Chaussy (Les Garennes), Val d’Oise,France,Lutetian;A, dorsal view;B, detailed view of the dots;C, abapertural view; D-H, MNHN A28968 (Houdas coll.),Chaussy (Les Garennes), Lutetian; D, ventral view; E, F, abapertural views (E negative view); G, dorsal view; H, detailed view of the dots. Scale bars: A, C-G, 10 mm; B, H, 2 mm. Photographs by C. Lemzaouda and P. Loubry (MNHN).