Description of Two New Species of Marine Gasteropod.
[Read before the Auckland Institute, November 9th, 1926; received by Editor, 22nd June, 1927; issued separately, 8th November, 1927.]
Family Turritidae H. & A. Adams.
Scrinum Hedley 1922.
C. Hedley, “A Revision of the Australian Turridae.” Records of the Australian Museum, vol. 13, No. 6, p. 258, 1922.
Shell small, oblong, rounded at each end, whorls few. Protoconch low, dome-shaped. Colour yellow and brown, uniform or variegated. No differentiation of fasciole area. Sculpture of obscure radial ribs and faint spiral grooves. Aperture rather wide, smooth within; sinus shallow, lip simple, canal short and wide, with an everted margin; columella concave and twisted.
Type. Mitromorpha brazieri Smith.
8 fath. Watson Bay (type).
“To Scrinum I would also refer Bela neozelanica Suter, from North N.Z.” (C. Hedley).
Scrinum sandersonae n. sp. (fig. 1).
Shell small, fairly solid, fusiform, polished. Sculpture consisting of strong rounded axial ribs, about twice breadth of intercostal spaces, extending from suture to suture on spire-whorls; on body-whorl not so prominent, and become obsolete before reaching periphery; 15 ribs on body-whorl, 12 on penultimate whorl. Fine unequally spaced spiral striations everywhere present, though less conspicuous on outer curvature of ribs. Whorls 4 regularly increasing, very slightly angled, shoulders faintly concave, the dark colour stripe intensifying the turriculate appearance of spire. Base concave, a slight constriction at neck. Spire elevated, conic, a little higher than height of aperture. Protoconch flattened globose, of about one whorl, smooth; nucleus depressed. Suture lightly impressed and regular. Aperture oblique, rather widely ovate, channelled above and terminating below in short open canal. Outer lip blunt, regularly convex, with shallow sinus at shoulder; basal lip everted somewhat and bounded by thickened rounded edge. Inner lip narrow, defined by a more or less vertical furrow on outer side, and highly glazed. Columella slightly arcuate, subvertical. Colour uniformly pale fawn, deeper on base, with broad spiral stripe on shoulder, light brown on post-nuclear whorl and gradually deepening to dark brown, which further becomes a milky
tinge and finally fades off as it approaches aperture. Operculum and animal unknown.
Diameter, 6.5 mm. Heigth, 12.5 mm. Angle of spire 40†.
Holotype in Author's collection.
Habitat. Matauri Bay, Whangaroa.
Remarks: Mr. A. W. B. Powell, who kindly compared this species for me with other allied forms, writes to say that “Scrinum neozelanica Suter, is a differently-coloured shell from sandersonae, proportionately narrower and with axial costae not extending above the shoulder”.
I have named this species in honour of Mrs. Sanderson of Totara North, Whangaroa, who discovered it, and to whom I am much indebted for this and many other specimens on previous occasions.
Mayena multinodosa n. sp. (fig. 2).
Shell large, rather thin, nodulous, with discontinuous varices. Sculpture consisting of numerous fine riblets, becoming more pronounced and distant towards base; everywhere crossed by fine growth-lines; axial ribs lightly indicated upper whorls, about 9 between varices, and also 5 equidistant spiral ribs upon each whorl; strong tubercles present at points of decussation; axials, spirals, and tubercles all tend to become obsolete at periphery of body-whorl. Strong varices present on opposite sides of shell, crossing whorls somewhat obliquely. They are ornamented with 5 strong transverse cords with finer cords between. Each varix being attached at its upper end to whorl above, results in a perfect echeloned formation. Whorls 9 regularly convex, base excavated at neck. Protoconch one and a-half smooth whorls, nucleus depressed. Aperture oblique, roundly ovoid, channelled above, by a strong quadrate tooth on parietal wall, and uppermost tubercle on outer lip. Outer lip broad and rather thin, presenting well-marked longitudinal groove, traversed by smaller grooves—indentations of the external cords; inner margin denticulate throughout its whole length. Inner lip forming a thin plate below, thick in middle third, and above lost in thin callus. Canal of medium length, outer border smooth, inner border bearing six well-defined teeth. Columella a little oblique, arcuate. Colour light brown, spiral sculpture a shade darker.
Diameter, 83 mm. Height, 163 mm. Angle of spire 40†.
Holotype in Author's collection.
Habitat. Cavalli Island, near Whangaroa, in 25 fathoms.
This species (four specimens) was secured recently by Mr. Eric Sanderson of Totara North, in cray-fish pots set in rocky grounds. Xenophalium royana Iredale, a further addition to our New Zealand molluscan fauna, has also been taken in similar circumstances in the same locality, the shells in each instance being introduced into the traps by hermit-crabs, Eupargurus novae zelandiae.