Seraphs sp. 1

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 : 434

Seraphs sp. 1 ( Figs 11 A-C; 12A-C)

Seraphs sp. – Merle et al. 2008: 200, pl. 25, fig. 3.

MATERIAL EXAMINED. — Lutetian, Chaussy (Les Garennes), Val d’Oise, 1 ex. ( MNHN A25011 , Faullummel coll.).

DESCRIPTION

Shell

Shell 13 mm in height and 4 mm in diameter, slightly inflated with short and blunt apex. Aperture long and narrow. Callus of the inner lip not preserved. Straight columella near the base. Outer lip very thin, not thickened and extending to the apex ( Fig. 11A, B ). Siphonal notch moderately deep on the dorsal side of the shell. No sculpture on the surface of the shell.

Colour pattern

The residual pattern is only composed of two levels of residual pigmentation:fluorescent axial stripes on a darker background. Th e stripes, sinuous overall, include some zigzags on short segments ( Fig. 12 A- C). They are rarely continuous on the whole height of the shell. Th eir width is variable.

COMPARISONS

The shell shape is indistinguishable from that of young S. volutatus and they share the lack of sculpture. However, the residual pattern of Seraphs sp. 1 is very different from that of all other Seraphs in showing axial sinuous stripes. Moreover, it is the only pattern showing light elements on a darker background.

DISCUSSION

Although the residual colour pattern of Seraphs sp. 1 is clearly distinct (no intermediate pattern) from that of S. volutatus and even from that of the other Seraphs , we believe that it is preferable to avoid the description of a new species, because of the strong intrageneric variability and the occurence of only one specimen having this pattern.

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. 12.— Seraphs Montfort,1810 shells under UV light:A-C, Seraphs sp.1, MNHN A25011 (Faullummel coll.),Chaussy (Les Garennes), Val d‘Oise, France, Lutetian; A, ventral view; B, abapertural view; C, dorsal view; D-F, Seraphs sp. 2, MNHN A28887 (de Morgan coll.), Fresville (Coteau de Vauville), Manche, France, Lutetian;D, ventral view; E, labral view; F, abapertural view. Scale bars: 10 mm. Photographs by C. Lemzaouda (MNHN).