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LUCINIDA |
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Notomyrtea botanica (Hedley, 1918) Description: A small-sized, thick-shelled lucinid. Shape subovate, moderately inflated, length greater than height, umbo on midline; lunule sunken but narrow, anterior dorsal margin weakly concave, anterior and ventral margins smoothly rounded, posterior margin truncate and weakly concave. Exterior with irregularly spaced concentric ridges, closer together ventrally, interspaces sometimes with dense axial threads that do not cross the concentric ridges (Fig. 2). Interior pitted inside pallial line, smooth outside pallial line; posterior muscle scar roughly circular, anterior elongate and narrower; pallial line continuous. Hinge left valve with 2 small cardinal teeth, lateral teeth absent or highly reduced; right valve with single cardinal tooth, prominent anterior lateral tooth and small posterior lateral. Ligament external, long. Shell white. Size: Up to 16 mm in length. Distribution: Endemic to Australia: Sydney, NSW, southwards and around southern Australia, to south-western WA, including Tas. Habitat: Subtidal, 15-200 m. Common. Comparison: This species is similar to Monitilora ramsayi in having concentric sculpture and axial threads between that do not cross the concentric ribs, but the two species differ in outline. Synonymy: This species is variable in the strength of the radial threads between the concentric ribs. Specimens from Victoria that possess strong radial threads were named Lucina mayi Gatliff & Gabriel, 1911, while larger specimens without radial threads from NSW were named Myrtea botanica Hedley, 1918. These are probably the same variable species, but until this is confirmed by genetic analysis Hedley’s name is retained. Fig. 1: Off Shark Island, Sydney Harbour (C.055340) Fig. 2: D’Entrecasteaux Channel, Tasmania (C179575) |
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