Scaeochlamys squamata (Gmelin, 1791)
GMELIN, J. F. 1791. Caroli a Linné, Systema Naturae per Regna Tria Naturae, secundum classes, ordines, genera, species, cum characteribus differentis, synonymis, locis. Tomus I. Pars VI. Classis VI. Vermes Species, cum characteribus, differentiis, synonymis, locis. 13th edition, Aucta, Reformata, 3021-3910 p. Impensis Georg Emanuel Beer, Lipsiae [Leipzig], 1791 [p. 3329]
1791 Ostrea squamata Gmelin, 1791
1853 Pecten tenellus Reeve, 1853
1933 Pecten (Pecten) subsquamatus Nomura, 1933
1853 Pecten tenellus Reeve, 1853
1933 Pecten (Pecten) subsquamatus Nomura, 1933
«Remarks: Reeve (1853) described the present species as follows: " Shell somewhat triangularly orbicular, thin, irregular, inequilateral, nearly equivalve, compressed, valves rayed with seven or more distantly scaled ribs, interstices between the ribs more or less broad, obscurely ridged; whitish, stained with light brown-flesh; ears nearly equal".
At that time he pointed out that the growth of this species is very irregular, and the ridges in the under valve being partially developed here and there into scaled ribs. The specimens collected from the Toukoushan Formation in the Houlung area, Miaoli Hsien, take the following description: Shell rather small in size, rather thin, compressed, higher than long, subequilateral except for auricles, inequivalve; valves radiately ribbed, forming an angle of about 80° at the apex. Right valve a little inflated or sometimes nearly flat, with 25 to 30, low, rounded, irregular, fine radial ribs which are unequal in strength; several radial ribs tend to become more distinct than others with growth and with prominent scales near the ventral margin; radial ribs near the submargins are usually with distinct fine scales; interspaces between the radial ribs nearly equal to or broader than ribs themselves in breadth, sometimes with a fine intercalary thread and with flne network; the anterior auricle much larger than the posterior one, with conspicuous byssal notch and wide byssal area having several finely imbricated fine radial threads; hinge with prominent ctenolium; the posterior one truncated behind at about right angles, and similar to the anterior in sculpture. Left valve moderately inflated, usually with irregular, highly scaled, prominent raidal ribs and a few, low radial ribs between prominent radial ribs; the anterior auricle much larger than the posterior one. The present species shows such a wide variation in surface sculpture as shown in the plate that the present species is frequently misidentified with Chlamys farreri (Jones and Preston), a Recent species of Southeast Asia, but farreri is distinguishable from the present one by its large, rather thick, moderately inflated shell and characters of radial ribs. The present species can be distinguished from Chlamys satoi (Yokoyama) described from the Byoritz Beds, Taipei and Miaoli Hsiens, by its small shell, smaller apical angle and unequal, distinctly scaled radial ribs and low, fine radial ribs between prominent radial ribs. However sometimes, it is rather hard to distinguish one from the other in the case of very young shells. Nomura (1933) proposed Pecten subsquamatus, n. sp. for the specimens from the Byoritsu Beds, but it is evident that his subsquamatus is a synonym of the present species.» MASUDA, K. & C. HUANG. 1994. Tertiary and Quaternary Pectinidae from northern Taiwan. Journal of the Geological Society of China, 37 (4): 497-549, pls. 1-10. [p. 506, 507]
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Chlamys (s.s.) squamata (Gmelin, 1791); K. Masuda & C. Huang, 1994, Tertiary and Quaternary Pectinidae from northern Taiwan, pl. 1, figs. 1-7.
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«Species pervariabilis tam formatione costarum majorum atque minorum, quam colore; costae enim primariae plus minusve squamigerae atque adeo sine ullo squamarum vestigio obveniunt; pariter color et picturae natura mutabiles sunt. Specimina Japonica ex parte colore vividissimo aurantio, coccineo et sulphureo picturaque concinna excellunt. Specimen aurantium in Tabula nostra depictum est.»
DUNKER, W. 1882. Index Molluscorum Maris Japonici. Casselis Cattorum. Sumptibus Theodori Fischer. 301 p., 16 pls. [p. 240]
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Pecten squamatus Gmelin (Ostrea).; W. Dunker, 1882, Index Molluscorum Maris Japonici, pl. 11, fig. 14.
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