Descriptions of Five New Land-Shells from New Zealand.
[Read before the Auckland Institute, 31st July, 1928; received by Editor, 3rd August, 1928; issued separately, 30th August, 1928.]
Murdochia aranea n. sp. (Fig. 1).
Shell small elongate-conical, subperforate thin and fragile. Whorls 6 including moderately large papillate protoconch of two smooth whorls. Post-nuclear whorls sculptured with close, white, membranaceous, obliquely-retractive riblets, about eleven per millimetre, interstices with exceedingly fine irregular spiral wrinkles. Body-whorl large almost equal to half total height of shell, ribleta continuous over base and converging into umbilical cavity. Spire tall, over 2½ times height of aperture. Peristome thin, discontinuous. Columella oblique, arcuate, a little reflected over narrow umbilical perforation. Colour dark reddish-brown, excepting the white riblets which stand out in sharp contrast.
Height 3 mm., diameter 1.5 mm.
Holotype and 3 paratypes in author's collection Auckland, 5 paratypes in collection of Mr. W. La Roche, Auckland.
Habitat: Opononi, Hokianga Harbour, under decaying leaves in native bush. (W. La Roche, April, 1928.)
Remarks: This species appears related to Suter's torquillum, but is easily distinguished by its much greater adult size and proportionately taller spire.
Aeschrodomus worleyi n. sp. (Fig. 2).
Shell small, conoidal-dome shaped, axially costate, widely umbilicated with rounded periphery and base. Whorls 5, including low rounded protoconch of 2 faintly spirally striated whorls. All post-nuclear whorls sculptured with prominent narrow, regular, closely-spaced, sharply raised, flexuous and retractive axial riblets, about 10 per millimetre. The interspaces crowded with exceedingly fine subsidiary axial threads and still finer close spiral threads, producing a fine even reticulation. Spire 1⅔ height of aperture. Whorls evenly convex, impressed at sutures. Base slightly flattened towards umbilicus which is wide and deep of about one-third of diameter. Aperture small subcircular. Peristome thin, discontinuous. Columella short, arcuate, slightly reflexed, and almost vertical. Parietal-wall covered with a thin glaze. Colour buff with irregular radial rectangular blotches of reddish-brown, becoming obsolete towards lower suture and not extending over periphery on body-whorl.
Height 2 mm., diameter 2.6 mm.
Holotype presented to Auckland Museum by Professor F. P. Worley.
Habitat: Near Baton River, Nelson (Professor F. P. Worley and Rev. F. Worley, 1897). Between Owen and Murchison, Nelson-West Coast Road (A. W. B. P., December, 1927). Under decaying wood in native bush.
Remarks: This species agrees very well with Aeschrodomus except that the riblets are not produced into hair-like processes at the periphery. The conoidal spire and striated protoconch however are typical characters discordant with the closely allied genus Charopa.
Egustula spectabilis n. sp. (Figs. 3 and 4).
Shell small, sub-discoidal, almost flat above peripheral angle, convex below, rapidly contracting over base into broad umbilical cavity. Whorls 3½, including protoconch of 1½ low, convex, finely spirally striated whorls. All post nuclear whorls covered with fine, close retractive axial riblets and regularly spaced, obliquely retractive radial lamellae, produced at periphery into broad bluntly-rounded thin plates, diminishing above towards suture and below towards umbilicus. Spiral sculpture in form of indistinct microscopic striae. Body-whorl slightly descending towards aperture. Aperture moderately large, rhomboidal. Peristome discontinuous. Outer lip thin, bluntly angled at centre. Parietal callus thin, crossed by two of the lamellae. Columella oblique, arcuate, slightly reflexed. Umbilicus about one-fifth width of base. Colour uniformly golden-brown.
Height 0.7 mm., diameter 1.5 mm.
Holotype presented to Auckland Museum by Professor F. P. Worley.
Habitat: Nelson (Professor F. P. Worley and Rev. F. Worley, 1897).
Cavellia spelaea n. sp. (Fig. 6).
Shell very large for the genus, discoidal, with sunken spire, broadly umbilicated and regularly radially costate. Whorls 4½, including smooth protoconch of 1½ low convex whorls. Post-nuclear whorls sculptured with numerous oblique, protractive, fine radial riblets about 9 or 10 per millimetre, persistent over whorls from spire to umbilicus. Interstices with exceedingly fine and close radial growth-threads. Body-whorl flattened above periphery, evenly convex below to broad perspective umbilicus, a little more than one-third width of base. Aperture pyriform, constricted above. Outer lip thin, protractive, overhanging above. Inner lip spread as a broad thin glaze over parietal wall. Basal lip slightly expanded and reflected at junction with parietal wall.
Height 2.5 mm., diameter, maj. 5.25 mm., min. 4.75 mm.
Holotype and six paratypes in author's collection Auckland.
Habitat: Coonoor Cave, near Dannevirke. Sub-fossil together with moa bones (Dinornis) and the common Recent bush snail, Charopa coma (Gray). (H. Hamilton, December 1914.)
Remarks: This is the largest species of the genus, readily distinguished by the flattened sides above periphery.
Laoma (Phrixgnathus) larochei n. sp. (Fig. 5).
Shell small, semitransparent, acutely conical. Spire slightly concave, almost three times height of aperture. Acutely angled and keeled at periphery, broadly umbilicated and rounded over base. Whorls 8, including rather large globular protoconch of 2 smooth whorls. Post-nuclear whorls scultpured with fine and close, retractive, arcuate growth-lines, much stronger on base. Suture distinct, margined above by a thread which later resolves into peripheral keel. The spire-outline is slightly concave and rendered a trifle gradate, due to the whorls coiling just under the keel. Base gently rounded. Umbilicus deep, rather narrow, about one-sixth diameter of base. Aperture rhomboidal. Peristome thin, discontinuous. Outer lip acutely angled at centre. Columella very short, vertical. Colour pale buff, semitransparent, regularly radially banded with light reddish-brown.
Height 2.25 mm., diameter 2.3 mm.
Holotype in author's collection Auckland, paratype in collection of Mr. W. La Roche, Auckland.
Habitat: Opononi, Hokianga Harbour, under decaying leaves in native bush. (Mr. W. La Roche, April 1928.)
Remarks: Related to the rare South Island marginata Hutton which, however, is less conical and has a much smaller umbilical cavity.