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Species / Struthiolaria Lawsei

Struthiolaria Lawsei

Stromboidea


Original Description of Struthiolaria lawsei by Powell & Bartrum, 1929:

  • "Shell sub-turbinate, large, with very large body-whorl and strongly gradate spire slightly higher than aperture; ornamented by very fine threads and very prominent elongated tubercles at the sharp angle of the whorls. Seven post-nuclear whorls; 2 in apex. Spire-whorls strongly angled and carinate at middle with nodules on the keel; almost flat above and below keel. Body-whorl strongly bi-angled, with secondary tubercular carina (poorly shown by holotype) on lower angle; below the angle it contracts rapidly at the base. On younger paratypes the lower keel is strongly raised and is fairly prominently and closely tubercular, the nodules twice as numerous as on upper carina, though becoming obsolete towards aperture. Protoconch has 2 flatly-coiled vertically-depressed whorls; these are followed by a convex whorl with 8 sharply-raised equidistant spiral threads; the next whorl is angled at the middle and has a keel crossed somewhat obliquely by minute close-spaced axial costae which resolve on the succeeding whorls into nodules. These continue to increase in prominence and finally become the prominent strongly-produced, vertically-compressed sharp carinated tubercles already noted; about 7 per whorl in lower whorls, but more numerous in upper whorls. In mature forms growth-stages appear to end with abnormal elongation of one of the spines into a spear-like excrescence from the outer lip . This seems to be coordinated with the partial or complete suppression of one or two preceding tubercles. Threads of spiral sculpture equidistant, very close and fine (about 3 per mm. on body-whorl) and covering whole of shell. On holotype and one or two large paratypes there is a strong spiral thread a little below lower keel, but this does not appear to be a constant character. Growth-lines faint. Aperture with callus of inner lip spread widely and very heavily on parietal wall and columella, the callus with sharply raised thick border, especially on base and near posterior notch, so that there is often a distinct and even prominent chink beneath it just below the lower angle of body-whorl. Callus not so high as in papulosa, for it does not extend beyond suture near posterior canal. Aperture notched in the usual fashion, the posterior notch very broad. Outer lip polished, generally strongly produced at both angles of body-whorl, especially at the upper, where it may be developed as the prominent spear-like process already described, with deep sinuses above and below it. Outer lip also very greatly thickened and little reflected, so that its external surface is broadly flattened."

Locus typicus: Oneroa, small bay north west coast of Waiheke Island, Waitemata, Auckland, North Island, New Zealand

Stratum typicum: Oligocene

Measurements Holotype: Height, 91.3 mm.; breadth (incomplete), 49.8 mm.

Struthiolaria lawsei Powell & Bartrum, 1929; Holotype; Oligocene; Oneroa, small bay north west coast of Waiheke Island, Waitemata, Auckland, North Island, New Zealand; ; Coll. Auckland Museum no. AK 72146; Copyright Auckland Museum

Etymology: The species is named in honour of Mr. C. R. Laws, M.Sc., a worker upon New Zealand Tertiary mollusks.

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