Chlamys midwayensis Habe & Okutami, 1968
HABE, T. & T. OKUTANI. 1968. Some new and interesting shells from the sea around Midway Island. Venus [Journal of the Malacological Society of Japan], 27: 47-56, pl. 3. [p. 50, pl. 3, figs. 2, 3]
Chlamys midwayensis sp. nov. (Pectinidae)
(PI. 3, figs. 2, 3)
«Shell is small, thin, slightly convex in both valves, circular in shape, with rather small ear-shaped processes at both anterior and posterior sides of the umbo. Anterior and posterior margins as well as hinge line are straight.
Of the left valve, the surface has about 14 to 16 primary riblets radiating from the umbo to the ventral margin. They are stained in reddish brown and armed by small scales on the top. The additional intercalated threads between them grow to weaker riblets towards the ventral margin, and are intercrossed with growth lines showing minutely reticulated sculpture on the surface. The anterior ear-shaped process is triangular in shape, larger than the posterior one, and ornamented with about ten radial riblets that are intersected by growth lines. The posterior ear is small, oblique to the umbo, with delicate radii. The left valve is pale brownish in color and riblets show brown. Of the right valve, the surface has about 50 subequal radial riblets which lack scales on the top. The anterior ear-shape process has distinct byssal notch with five minute teeth anteriorly. The posterior ear is small and oblique. The right valve is yellowish white throughout. Inner surfaces of the both valves are white and shining with a brownish tint in the umbonal region. Muscle scars are normal for the genus. Measurement: Length 19.9 mm, height 22.0 mm, breadth 6. 1 mm (figured holotype preserved in the National Science Museum).
Length 17.8 mm, height 19.8 mm, breadth 5.3 mm (Paratype) Locality: Lat. 35°15'N, long. 171°50'E, 400 ~ 460 m deep.
Remarks: Chlamys kauaiensis DALL, BARTSCH & REHDER is an allied species in its small size and thin shell, but has about 25 regularly arranged and subequal-sized radial riblets. Chlamys hawaiiensis DALL, BARTSCH & REHDER is another ally in shape, but
has only about 15 strong but low radial ribs and many radial riblets. Chlamys jousseaumei BAVAY from Japanese waters may be an ecological equivalent to the present new species.» TADASHIGE HABE & TAKASHI OKUTANE, 1968
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T. Habe & T. Okutani, 1968. plate 3.
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