Risssoina obliquecostata n. sp. (Plate VI, fig. 1.)
Shell small, ovato-elongate, deeply impressed sutures and oblique axial riblets. Whorls six (the protoconch missing), rounded and narrowly shouldered, the last slightly produced at the anterior end. Sculpture consists of about twenty-nine narrow axial riblets, in width about half that of the interspaces, on the sutural shelf they are rather less pronounced, form a
Fig. 1.—Rissoina obliquecostata n. sp.
Fig. 2.—Seila attenuissima n. sp.
Fig. 3.—Triphora aoteaensis n. sp.
Fig. 4.—Siphonalia senilis n. sp.
Figs. 5, 5a.—Admete suteri n. sp.
Fig. 6.—Admete anomala n sp.
Fig. 7.—Surcula hampdenensis n. sp.
Fig. 8.—Borsonia zelandica Marshall
Fig. 9.—Conus armoricus Suter (protoconch).
Fig. 10.—Conus armoricus var. pseudoarmoricus n. var.
row of small nodules on the angle, thence take a backward sweep, and vanish a little above the suture, on the anterior end of the last irregular and here and there in the form of strong growth-striae; spiral striae are preserved in places only and difficult to detect. There is a narrow, subperforation at the side of the columella, bounded by a small funicular ridge which curves around to the basal lip. Aperture oval, narrow above, basal lip slightly produced and with a lightly impressed gutter at its junction with the columella, inner lip with a thin narrow callus, columella slightly curved and a little reflexed anteriorly.
Length, 6.25 mm.; width, 3.5 mm.; length of aperture, 2.5 mm.
Locality, Hampden. Collected by Dr. Marshall.
Type to be presented to the Wanganui Museum.
There is a single example only. It is very different from any other of our Recent or fossil Rissoids, and it is with hesitation we refer it to the genus. More material may be brought to light, possibly allied forms which would lead to a more confident classification.