Decatopecten radula griggi (Webb, 1957)
WEBB, J. H. 1957. New form of Pecten. The Nautilus, 71: 53-54. [p. 53, pl. 4, figs. 1-3]
1957 Pecten (Comptopallium) radula griggi Webb, 1957
J. H. Webb, 1957, plate 4.
|
«Shell triangularly ovate, equilateral and equivalve. Posterior and anterior margins perfectly straight from the umbones to the outer margin and both drop off peculiarly at right angles leaving the edges flat. Holotype 50.8 mm. in height and 50.5 mm. in lengh. All paratypes similar in proportion but vary in size f'rom 31 mm. high to 50.8 mm. Left valve very flat and peculiarly compressed at the umbone. Right valve convex. Byssal notch small with three denticles on lower margin. Shell white with left valve maculated with brown and black. Right valve white. Both valves yellow at the umbones. Hinge line stright and stained with coffe-brown on interior. Auricles very large and equal. Auricles on both valves are radially ribbed with three main ribs which are squamate. Ribs number nine or ten and are rounded with the tops of each, on both valves, covered with crowded scales or fimbriations about half the length of rib starting at the outer margin. Sides of ribs and bottoms of interstices are smooth. Both ribs and interstices rounded and of practically the same size.
Holotype and several paratypes were taken at Escape Pass near Cape Leveque in N. W. Australia from tidewater to six fathoms. Holotype in The Academy of Natural Sciences of Philadelphia, No. 225038. The specimens examined were taken in shallow water at low tide. Although Murex, Cypraea, Conus and Mitra were also taken the only other Pecten taken near the locality was P. (Comptopallium) radula Linné. P. radula is narrow and elongate with ten to fourteen rounded broad ribs with radial ribbing covering them and fine concentric lines crossing them, giving the shell a granular appearance. It has no scales or fimbriations and the left valve is slightly convex. Recently some shells taken at the Palau Islands have many of the characteristics of this new variant. However the Palau I. shells have a slight curve in the posterior and anterior margins, the left valve is not as flat and the scales or fimbriations are not as pronounced. These slight differences may be entirely due to local genetic or ecologic variations. The author wishes to acknowledge and thank Dr. Harold Rehder of the Nat. Museum in Washington, Dr. Tucker Abbott of the Academy of Nat. Sciences of Philadelphia and Dr. Leo G. Hertlein of the Cal. Academy of Sciences in San Francisco for their help in identifying this shell.» J. H. WEBB, 1957
|
«Webb (1957: 53) introduced a new form, Pecten (Comptopallium) radula var. griggi, from northwestern Australia. According to ICZN (1999: 50, Article 45.6.4) this taxon should now be treated as a subspecies, although we do not recognize it as a formal geographical subspecies.»
DIJKSTRA, H. H. & A. G. BEU. 2018. Living scallops of Australia and adjacent waters (Mollusca: Bivalvia: Pectinoidea: Propeamussiidae, Cyclochlamydidae and Pectinidae). Records of the Australian Museum, 70 (2): 113-330, figs. 1-102. [p. 186]
|