"Chlamys" pollux (Orbigny, 1850)
ORBIGNY, A, D'. 1850. Prodrome de Paléontologie stratigraphique universelle des animaux mollusques et rayonnés. Premier Volume. 394 pp. Victor Masson. Paris [p. 220]
1850 Pecten pollux Orbigny, 1850
1891 Pecten amphiarotus Di Stefano, 1891 [nomen novum pro Pecten seguenzae Di Stefano, 1886].
1891 Pecten amphiarotus Di Stefano, 1891 [nomen novum pro Pecten seguenzae Di Stefano, 1886].
Pecten Pollux d'Orb.; A. Thevenin, 1907, Types du Prodrome de paléontologie stratigraphique universelle de d'Orbigny, plate 23, figures 16, 17.
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«135. PolIux. d'Orb., 1847. Très-belle espèce à grosses côtes inégales, dont quelques-unes sont porvues de très-longues pointes tubuleuses. Au-dessous de l'O. arcuata, à Pouilly (Côte d'Or).»
ALCIDE D'ORBIGNY, 1850
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«2. AMENDED DIAGNOSIS
Distinguished from both Ch. (Ch.) textoria and Ch. (Ch.) valoniensis by the presence of long tubular spines.
3. AMENDED DESCRIPTION
Shape essentially similar to Ch. (Ch.) valoniensis. Differing only by the somewhat larger H/UA, by the slight ontogenetic reduction in the relative size of the byssal notch and by the tendency for the anterior auricles to meet the hinge line at a right angle.
Both valves ornamented with between 22 and 27 (usually 24) rounded radial plicae. Those on right valve low, equal in size, and up to 50% bearing tubular spines up to 5 mm in length, set at intervals of about 5 mm (PI. 9, Fig. 7). Those on left valve markedly unequal in size, 5-7 being larger and bearing robust tubulär spines up to 10 mm in length, spaced at intervals of about 10 mm (PI. 9, Fig. 8). Spines absent from both valves at shell heights below about 1 mm. Sulci equal in width to plicae; both traversed by closely spaced fine comarginal striae. Hinge line of right valve bearing dorsally directed spines up to 5 mm in length, spaced at intervals of 2-3 mm. Shell thickness moderate. Maximum height 53 mm (BM L65791). 4. DISCUSSION
The two syntypes of 'Pecten' Pollux D'ORBIGNY are both right valves, one of which (MNS 1591) is well preserved while the other (MNS 1591 A) is somewhat abraded. The former is herein designated as lectotype. Although brief, D'ORBIGNY's (1850) diagnosis and description could refer to no Sinemurian pectinid other than the species described in Section 3. There is consequently no doubt that the first taxonomically valid use of 'P.' pollux was in 1850 (see ICZN Opinion 126) and that therefore D'ORBIGNY's species is the senior synonym for the species described in Section 3.
DI STEFANO (1891) provided no illustration of 'P.' amphiarotus but mention in the description of spines and unequal plicae leaves little doubt that the species (from the L. Lias) is synonymous with Ch. (Ch.) pollux. TRAUTH's (1909) misapplication of DI STEFANO's specific name is discussed under Pseudopecten (Ps.) dentatus. Since LENTINI (1973) referred to 22 'ribs' in his description of Ch. ('Aequipecten') amalthea (OPPEL) his use of this specific name is undoubtedly outside OPPEL's (1858) hypodigm (= Propeamussium (P.) pumilum). The figured specimen (from the L. Lias) appears to exhibit abraded spines and therefore may well be conspecific with Ch. (Ch.) pollux.» JOHNSON, A. L. A. 1984. The palaeobiology of the bivalve families Pectinidae and Propeamussiidae in the Jurassic of Europe. Zitteliana, 11: 1-235, pls. 1-11. [p. 186]
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Chlamys (Chlamys) pollux (d'Orbigny 1850); A. L. A. Johnson, 1984, The palaeobiology of the bivalve families Pectinidae and Propeamussiidae in the Jurassic of Europe, plate 9, figures 7, 8.
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«Diagnose originale. — "Très belle espèce à grosses côtes inégales dont quelques-unes sont pourvues de très longues pointes tubuleuses. Au-dessous de l'O. arcuata, `s Pouilly (Côte-d'Or)."
Observations. — Cette espèce a été figurée et décrite avec détails par Dumortier. (Études paléont., sur les dépôts jurass. du bassin du Rhône. Infra-lias. P. 65, PI. X, fig. 11, 12 et Pl. XI, fig. 1, 2, 3, 4.) On remarquera pourtant que l'ornementation de l'oreillette antérieure du type de d'Orbigny est un peu différente des figures données par Dumortier. Explication des figures. —Pl. IX, fig. 16, 17. Deux échantillons différents (valves droites) provenant de Pouilly. Coll. d'Orbigny, no s 1591 et 1591 A. Grandeur naturelle.» THEVENIN, A. 1907. Types du Prodrome de paléontologie stratigraphique universelle de d'Orbigny. Tome 1: Silurien - Bathonien. Annales de Paléontologie, 2 (4): 161-172, pls. 23, 24. [p. 167]
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Pecten Pollux (d'Orbigny); E. Dumortier, 1864, Études Paléontologiques sur les Dépots Jurassiques du Bassin du Rhone, Première Partie, plate 10, figures 11, 12. [non Pecten pollux Orbigny, 1850: Pecten praepollux Hahn, 1910; fide T. R. Waller & L. Marincovich Jr., 1992, p. 223]
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