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NUCULIDAE |
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Pronucula covra (Bergmans, 1978) Description: Shell minute, thin. Shape equivalve, inequilateral with umbones behind midline, umbones low; inflated; anterior end broadly rounded; posterior end truncate. Hinge taxodont with strong teeth, with up to 5 anterior and 3 posterior teeth. Chondrophore small, vertical, hardly projecting beyond hinge plate. Interior smooth, margin weakly crenulate. Exterior with relatively narrow radial ribs across entire surface which are constant in strength, and numerous fine concentric growth lines; radial ribs and growth lines do not form a decussate texture where they intersect. Periostracum unknown. Shell colour white or colourless transparent. Size: Up to 1.58 mm in length. Distribution: Known from Twofold Bay, NSW, southwards to Cape Wiles, SA, including Tas. Habitat: Subtidal, 183-366 m. Synonymy: None. Comparison: This is a minute species with exterior radial ribbing. It differs from Nucula decorosa by having fewer hinge teeth, and by having radial ribbing on the entire shell, not just the anterior and posterior ends. Fig. 1: 7615-1 25 miles (40 km) east of Twofold Bay, NSW, in 294-304 m (C.100955 PARATYPE)
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