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MYTILIDAE |
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Musculus ulmus Iredale, 1936 Description: Shell equivalve, inequilateral, elongate, inflated, oval in outline, not wider posteriorly; umbo behind anterior end, incurved, projecting above dorsal margin. Hinge without teeth. Ligament short. Exterior with 3 sculptural panels; anterior panel with about 15 flattened radial ribs with narrow grooves; posterior panel with about 20 similar ribs; central panel with only concentric growth ridges. Interior with exterior sculpture showing through, muscle scars not apparent. Colour of shell white. Periostracum thin, pale green. Size: Up to 13 mm in length. Distribution: The Australian Museum collection holds specimens from Yamba, NSW, southwards and around southern Australia to the Recherche Archipelago, WA, including Tasmania. Habitat: Intertidal and subtidal. Macpherson & Gabriel (1962) said it was found living in association with ascidians. Comparison: This is a distinctive species with fine, uniform radial sculpture the same on the anterior and posterior ends, with a pale green periostracum over a white shell. Fig. 1: Twofold Bay, NSW (C.336587) |
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