Palliolum incomparabile (Risso, 1826)
RISSO, A. 1826. Histoire Naturelle des Principais Productions de l'Europe Méridionale et Particulièrement des Celles des Environs de Nice et des Alpes Maritimes. Tome Quatrième, vii, 439 p., pls. 1-12. Imprimerie de Lachevardiere Fils, Paris [p. 302, pl. 11, fig. 154]
1826 Pecten incomparabilis Risso, 1826
1826 Pecten vitreus Risso, 1826
1836 Pecten testae Bivona in Philippi, 1836
1846 Pecten furtivus Lovén, 1846
1858 Pecten forestii Martin in Gay, 1858
1860 Pecten tornabeni Biondi Giunti, 1860
1826 Pecten vitreus Risso, 1826
1836 Pecten testae Bivona in Philippi, 1836
1846 Pecten furtivus Lovén, 1846
1858 Pecten forestii Martin in Gay, 1858
1860 Pecten tornabeni Biondi Giunti, 1860
A. Risso, 1926, plate 11.
|
«P. Testa rotundata, glabra, nitida, hyalina; valva dextra striolis concentricis divaricantibus sculpta; epidermide glauco-pallida, striis eburneis fulmineis ornata; valva sinistra strlolis concentricis divaricantibus sculpta; epidermide glauca, eburneo reticulata.
Coq. arrondie, lisse, luisante, translucide, à valve droite, d'un glauque pâle, ornée de stries blanches flambées, et sculptée de petites stries concentriques, écartées; et à valve gauche glauque, réticulée de blanc, garnie de petites stries concentriques distantes. Long. 0,014. Séj. Profondeurs coralligènes. App. Été.» ANTOINE RISSO, 1826
|
«Palliolum is regarded here as the stem genus of the tribe. Among its oldest species are Palliolum prestwichi (Morris, 1852) from the Thanetian, Palliolum vincenti (Glibert 1933) from the lower Lutetian, P. nysti (G. Vincent, 1881) from the middle Lutetian, and P. decussatum (Münster in Goldfuss, 1833) from the Rupelian, all of which occur in northern Europe. Fossil species of the extant species Palliolum incomparabile (Risso, 1826) have been reported from rocks as old as Chattian (Baldi 1973: 183). Collectively these fossil species have posterior auricles that are shorter than the anterior ones in length and have convex to nearly straight posterior auricular margins that tend to form obtuse angles with the hinge. If radial costae are present on the disk, they are fine and numerous and tend to be continuous from early ontogeny. In these costate forms, coarse antimarginal striae commonly cross over the costae rather than being restricted to rib interspaces as in Dhondtichlamys. All auricles are multicostate regardless of whether costae are present on the disk. The extant species Palliolum striatum and P. incomparabile retain most of these ancestral features. The latter is the type species of the genus (subsequent designation by Crosse; see Hertlein 1969: N354).»
WALLER, T. R. 2006. New Phylogenies of the Pectinidae (Mollusca: Bivalvia): reconciling Morphological and Molecular Approaches. In S.E. Shumway & G.J. Parsons (Ed.) 2006: Scallops: Biology, Ecology and Aquaculture, 1-44, figs. 1.1-1.4. [p. 17]
|
Distribution. — From the boreal NE. Atlantic to the tropical E. Atlantic, including the Mediterranean Sea, liüng littorally to abyssal depths, byssally attached to rocks or amongst algae or rubble on muddy or sandy bottoms. Depth range of present material 54-300 m, living at 77 m.
Description. — Shell up to c. 18 mm in height, usually smaller, depressed, fragile, semitransparent, polychrome, slightly orbicula¡ somewhat equivalve and equilateral. Right valve more convex than left valve. Auricles strongly unequal in size; umbonal angle c. 95°. Both valves sculptured with microscopic antimarginal striae, intersected by minute commarginal growth lines and with delicate scaly radial riblets, more prominent near ventral margin. Anterior auricles with radial and commarginal sculpture, posterior auricles with radial sculpture. Hinge line straight. Byssal notch rather narrow, byssal fasciole weak. Active ctenolium with 3-5 teeth. Resilifer elongate and triangular. Left valve somewhat more brightly coloured than right one. Remarks. — Some authors (Nordsieck, 1969: 43; Tebble, 1976: 62; Lucas, 1979: 16) treated P. testae and P. furtivum as distinct species or subspecies of P. incomparabile, mainly based on the presence of radial sculpture on the disc, which is usually absent in P. incomparabile. However, this sculpture is often missing and very variable when present, also in the observed material (MNHN, NNM, SMNH, ZMA, ZMUC) from the eastern Atlantic. The material from the Azores usually has a radial sculpture. DIJKSTRA, H. H. & J. GOUD. 2002. Pectinoidea (Bivalvia, Propeamusidae & Pectinidae) collected during the Dutch CANCAP and MAURITANIA expeditions in the south-eastern region of the North Atlantic Ocean. CONCAP-Project contribution Nº 127. Basteria, 66: 31-81, figs. 1-77. [p. 50]
|
Pecten testae Bivona; J. G. Hidalgo, 1870-1890, Moluscos marinos de España, Portugal y las Baleares, plate 35A, figures 8-10.
|
«Rapports et différences. — Ch. tigrina, donne parfois des variétés lisses, assez voisines de Ch. incomparabilis par l'ornementation microscopique, mais elles se distinguent par leur forme et par l'inégalité plus grande des oreilles.
Ch. striata, outre l'ornementation microscopique, possède une ornementation radiale particulière. Distribution stratigraphique et géographique. — Actuellement Ch. incomparabilis se trouve sur les fonds coralligènes de la Méditerranée. Dans l'Atlan tique, elle ne semble pas dépasser les profondeurs du golfe de Gascogne. A l'état fossile, elle se trouve, quoique rare, dans le Pliocène et le Quaternaire italiens. Une valve gauche dans le Plaisancien du torrent d'Albanda (Catalogne), nommée par Almera P. tigerinus, appartient à Ch. incomparabilis. Les citations dans le Miocène de Styrie nous semblent très incertaines.» ROGER, J. 1939. Le genre Chlamys dans les formations néogènes de l'Europe. Conclusions générales sur la répartition géographique et stratigraphique des Pectinidés du Tertiare Récent. Mémoires de la Société Géologique de France [Nouvelle série], 17 (2-4): 1-294, pls. 1-28. [p. 205]
|
Chlamys incomparabilis Risso; J. Roger, 1939, Le genre Chlamys, plate 20, figures 7a, 7b.
|