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TRIPHORIDAE |
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Monophorus nigrofuscus (A. Adams, 1854) Description: Shell medium-sized, sinistral. Protoconch lecithotrophic, of 2½-2¾ whorls, with 2 spiral threads and numerous axial riblets. Teleoconch whorls convex with 4 beaded spiral cords and axial costae; spirals 1-4 commence immediately after protoconch; spiral 4 entirely exposed on all whorls. Another 2 spiral ribs on base (numbered 5 and 6). Spirals 1-3 of similar size on penultimate whorl. Axial costae of similar strength to spirals, nodulose at intersections, 18-24 on penultimate whorl. Outer lip of aperture flared, anterior siphonal canal slightly upturned, posterior canal a broad triangular notch. Protoconch and earliest teleoconch whorls fawn or white; subsequent whorls either buff-white or reddish to yellowish brown, or maculated; base darker. Size: Mature specimens 4.5 - 13.3 mm in length. Distribution: Endemic to Australia: Angourie, NSW, southwards and around southern Australia to central SA, including Tasmania. Habitat: Living specimens are known from the intertidal zone on rocky shores. Empty shells are know from beach washup down to about 150 m. Common. Comparison: This is much more common than most of the NSW triphorids, and is distinguished by having all of the spiral cords starting together immediately after the protoconch. Synonymy: Triphora cinerea Hedley, 1903 is a synonym. Remarks: This species varies widely in number of whorls at maturity (9½-17½) and in shell length (15.5-13.3 mm), as reported by Marshall (1983, p. 28). Figs. 1, 2: Long Reef, Collaroy, NSW (C.064078) Fig. 3: From Hedley, 1903, pl. 33, fig.35 |
Copyright Des Beechey 2015