"Mimachlamys" kauaiensis (Dall, Bartsch & Rehder, 1938)
DALL, W. H., P. BARTCH & H. A. REHDER. 1938. A manual of the Recent and fossil marine pelecypod mollusks of the Hawaiian Islands. Bernice P. Bishop Museum Bulletin, Honolulu, 153: iv, 233 p., pls. 1-58. [p. 92, pl. 22, figs., 9-10]
1938 Chlamys kauaiensis Dall, Bartsch & Rehder, 1938
W. H. Dall, P. Bartsch & H. A. Rehder, 1938, plate 22.
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«Shell small, white, subcircular, the auricle of the right valve strongly produced and marked by a strong tumid area at the dorsal margin and five radiating threads which grow consecutively smaller. The byssal notch is rather small. In addition to this, the auricle is marked by rather coarse incremental lines which form sublamellar cords on the dorsal tumid area. The posterior wing is very narrow, and is also marked by a tumid area at its dorsal margin and two slender threads. The incremental lines here are less strongly developed. The central portion of the shell has the anterior border strongly denticulated. The rest of the shell is marked by 25 very regular radiating threads which are about one third as wide as the spaces that separate them. In addition to this, there are fine incremental lines and numerous oblique scratches which show up best in the intercostal spaces. Interior of the shell diaphanous, showing the external markings within even the fine crisscross sculpture.
The unique type, U.S.N.M. Cat. No. 335674, was dredged by the U. S. Bureau of Fisheries Steamer Albatross at Station 4132 near Kauai in 257-312 fathoms on fine gray sand and mud bottom; bottom temperature 46.8° F. It measures: height, 6.2 mm.; length, 6.1 mm.; diameter of single valve, 1.5 mm. This species difiers from the other Hawalian Chlamys by having the ribs of one uniform strength.» WILLIAM HEALEY DALL, PAUL BARTCH & HARALD ALFRED REHDER, 1938.
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«Description. — Shell fragile, up to c. 6 mm high, nearly circular, weakly inflated, right valve slightly more convex than left valve, equivalve, anterior and posterior auricles unequal in size, umbonal angle c. 90-95˚. Prodissonch c. 240 μm in height. Colour creamy, whitish, yellowish, orange or reddish, sometimes with small white spots. Both valves sculptured with 24-28 regularly spaced, delicate scaly radial riblets, Microsculpture of granular, antimarginal and commarginal intercostal scratches. Auricles with 3-6 scaly radial riblets, crossed by commarginal riblets on anterior auricle of left valve. Antero-dorsal margin of anterior auricle of right valve strongly denticulated. Hinge line straight. Byssal notch moderately deep, byssal fasciole rather broad. Functional ctenolium with 4-6 denticles. Internal plicae from central part to ventral margin.
Distribution. — Hawaiian Islands, Coral Sea, New Caledonia, Loyalty Islands, Fiji and Tonga (Raines & Poppe, 2006: 202; Dijkstra & Maestrati, 2008: 107). Present specimen from the Philippines alive in 62-120 m (minimum depth range). Living amongst coral rubble or gravel on sandy or muddy sand bottoms. Remarks. — The present specimens are morphologically indistinguishable from the type specimen. A closely looking species is “Laevichlamys” allorenti (Dijkstra, 1988) known from the southwestern region of the Indian Ocean. Recently Dijkstra & Maestrati (2010: 348) described another closely looking species, provisionally placed in Mimachlamys, from the Austral Islands, M. erycina, which also belongs in this group. Shell characters (reticular sculpture on anterior auricle of left valve, vesicles or hollow sections on both sides of the radial ribs on the left valve, granular and commarginal intercostal microsculpture) of the present species do not justify placement in Chlamys, Laevichlamys or Mimachlamys. Perhaps this group of species could be more appropriately placed in Cryptopecten and is currently under study. This species is a new record for the Philippines.» DIJKSTRA, H. H. 2013. Pectinoidea (Bivalvia: Propeamussiidae and Pectinidae) from the Panglao region, Philippine Islands. Vita Malacologica, 10: 1-108, pls. 1-32 pls, 2 tabs. [p. 93]
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“Mimachlamys” kauaiensis (Dall, Bartsch & Rehder, 1938); H. H. Dijkstra, 2013,
Pectinoidea from the Panglao region, pl. 21 figs 4a-4b. |
«Mimachlamys erycina n. sp. is morphologically closest to M. kauaiensis (Dall, Bartsch & Rehder, 1938), from Hawaii and the southwestern Pacific. It differs in size (up to 11 mm in height, vs 6.5 mm in M. kauaiensis), in having fewer radial riblets (20-24, vs 24-27 in M. kauaiensis), in lacking commarginal sculpture on the left valve (prominent antero-laterally in M. kauaiensis), in having a delicate row of hollow sections on each side of the radial riblets of the left valve (lacking in M. kauaiensis). Mimachlamys kauaiensis was formerly often placed in Chlamys or Laevichlamys (Dijkstra 1995a: 57), but is actually more appropriately classified in Mimachlamys (Paulay 2003).»
DIJKSTRA, H. H. & P. MAESTRATI. 2010. Pectinoidea (Mollusca, Bivalvia, Propeamussiidae, Entoliidae and Pectinidae) from the Austral Islands (French Polynesia). Zoosystema, 32 (2): 333-358, figs. 1-5. [p. 350]
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