Go to National Library of New Zealand Te Puna Mātauranga o Aotearoa
Volume 51, 1919
This text is also available in PDF
(738 KB) Opens in new window
– 96 –

Art. XII.—New Fossil Mollusca.

[Read before the Auckland Institute, 20th December, 1918; received by Editor, 30th December, 1918; issued separately, 14th May, 1919.]

Plate VII.

The following Mollusca have mainly been collected from fossiliferous sands near the mouth of Kawa Creek, about fourteen miles south of the mouth of the Waikato River, which are described by the author in another paper in this volume (pp. 101–6). One—Chione auriculata n. sp. —was collected by the author when in company with Dr. Marshall at Pakaurangi Point, near Batley, Kaipara Harbour, in 1916; another—Bittium camaruticum n. sp.—was within a large gasteropod collected by Dr. Marshall from the Hutchinson's Quarry beds at Oamaru and given to the author; whilst there is one—Raeta tenuiplicata n. sp. — which was collected by Mr. R. P. Worley from the Okahukura Tunnel. All were submitted to the late Mr. H. Suter for identification, and pronounced by him to be new species.

In addition to Chione auriculata n. sp. there was identified also by Mr. Suter, from the Pakaurangi Point beds, along with other fossils collected by the writer, a specimen of Mesalia striolata (Hutt.), a species not listed by Dr. Marshall in his recent paper.*

Bittium oamaruticum n. sp. (Plate VII, fig. 1.)

Very small elongate tapering shell of 11 very slightly convex whorls increasing gradually in size. Protoconch 2 ½ whorls, smooth; the other whorls with strong subvertical rounded axial ribs subequal in width to the interspaces, and made slightly nodular by 6 or 7 prominent rounded spiral threads with linear interspaces. The radial costae are 13 in number on later whorls, dying out on flattened base of body-whorl. Only one or two spiral threads on base below the angle of the body-whorl. Sinuous growth-lines distinct on base. Suture fairly deep, margined. Columella smooth, oblique, imperfect. Aperture imperfect, one-third of body-whorl being absent; would appear to have been narrowly ovate and notched posteriorly. Inner lip very narrow, a mere film on body-whorl.

Length, approximately 5 mm.; diameter, 1·7 mm.

Holotype in Auckland University College collection

Locality: Hutchinson's Quarry beds. Collected by Dr. P. Marshall, 1917.

Remarks.—Classed as a new species of the genus by the late Mr. H. Suter, though the lack of knowledge of the aperture appears to render the generic position somewhat uncertain. If correctly placed, this genus is now for the first time described fossil from New Zealand rocks.

[Footnote] * P. MArshall, The Tertiary Molluscan Fauna of Pakaurangi Point, Kaipara Harbour, Trans. N.Z. Inst., vol. 80, pp. 263–78, 1918.

– 97 –

Chione auriculata n. sp. (Plate VII, fig. 2.)

Rounded-quadrate, small, rather compressed shell, almost equilateral; posterior end squarely truncated. Lunule large, lanceolate, very sharply raised at dorsal margin into a prominent triangular ear-like portion; margins sharply incised. Beaks rather small, little raised, approximate; a distinct ridge from beak to lower angle of truncated posterior end of shell.

Anterior dorsal margin forming triangular projection at lunule, the anterior side of triangle shortly forming an angle with the rounded anterior end. Posterior dorsal margin descends gently in convex curve to prominent angle with straightly truncated posterior end. Broadly rounded basal margin forms distinct angle at posterior end, and merges gradually into rounded anterior end.

Concentric ornamentation prominent; growth-lines are densely crowded and crossed by innumerable microscopic radiate lines. On lower half of shell are strong, broad, rounded lamellae, distant and somewhat irregular, 6 almost complete lamellae visible. They broaden out at posterior ridge of shell, and on dorsal portion beyond this are others nearer to the beak not developed anteriorly beyond this ridge. The lamellae crowd on the lunule, making it platy.

Hinge and other internal characters could not be observed.

Length, 10–6 mm.; height, 9 mm.; diameter, 4–6 mm.

Holotype in author's collection; complete but for anterior half of left valve.

Locality: Pakaurangi Point, Kaipara Harbour. Collected by Bartrum, 1916.

Circulus cingulatus n. sp. (Plate VII, figs. 3 and 4.)

Very small, umbilicate, almost discoidal shell, coiled in a very flat spiral. Whorls 3½ or 4, very rapidly increasing, the protoconch smooth, the rest sculptured by prominent spiral, angular, sharply elevated raised bands: 5 of these are visible between the sutures on penultimate whorl, 15 on body-whorl, regularly distributed, about 8 on basal portion, but absent from umbilicus. Interspaces approximately equal in width to the ridges, striated strongly by closely spaced transverse growth-lines, which alone ornament umbilicus.

Aperture somewhat incomplete, apparently circular, with a minute posterior sinus. Outer lip partially incomplete in holotype, moderately sharp, slightly crenate externally owing to spiral sculpture. Inner lip fairly solid, forming partial margin to the umbilicus; this latter not widely open and showing no coiling of whorls.

Diameter, 4 mm.; height, 1–9 mm.

Holotype and two imperfect paratypes in author's collection.

Locality: Kawa Creek, south of Port Waikato. Collected by Bartrum, 1917.

Remarks.—The late Mr. Suter remarked that this species comes nearest to C. politus Sut., from which, however, it is quite distinct.

Raëta tenuiplicata n. sp. (Plate VII, figs. 5 and 6.)

Shell of moderate size, very thin, obovate in outline, anterior end rounded, posterior produced and angled. Apparently agape anteriorly. Beaks directed forwards, sharp, fairly swollen, on posterior half of shell, approximate. From just below the beak a distinct wide shallow sinus passes

– 98 –

vertically to basal margin, giving shell a folded aspect. Anterior dorsal margin descends gradually, straight at first and then according with broadly convex anterior end. Posterior dorsal margin incomplete; descends steeply, apparently slightly concave, to narrowly produced posterior end. Anterior end rather imperfect, but evidently angled with gently sinuous basal margin, which rises obliquely towards narrowing posterior end.

Lunule not marked off, raised centrally, oval. Ornamentation shown only on isolated remnants of original surface; narrow, shallow concentric grooves, somewhat irregularly excavated, closely spaced, about 2 per millimetre. Radiate close lines visible on surface of cast but not on shell itself. Hinge and other internal characters unknown.

Length, actual 37 mm., restored approximately 42 mm.; height, 32 mm.; diameter, 18 mm.

Holotype and one paratype (both imperfect) in Auckland University College collection.

Locality: Okahukura Tunnel. Collected by R. P. Worley, 1916.

Siphonalia propenodosa n. sp. (Plate VII, figs. 7 and 8.)

Oval turreted shell, solid, fairly large, closely approaching S. nodosa (Mart.) but distinct in sculpture. Whorls 8 ½, protoconch apparently 2½ whorls, the first smooth, the others axially costate. Spire short, angle 55°, whorls gradually increasing. Suture not impressed, slightly sinuous. Whorls somewhat angled, and lightly excavated above the angle. Aperture imperfect on the holotype, but well shown in a paratype; high, oval; outer lip fairly thin, slightly callous, and finely notched or crenulate within, faintly angled at both keels of body-whorl. Posterior notch very distinct; anterior canal oblique, strongly recurved, broad, short, and truncated at base. Columella slightly excavated above and inflected to the left at canal. Inner lip spread broadly on body-whorl; siphonal fasciole distinct, crossed by coarse lamellae. Height of aperture and canal about twice height of spire.

Ornamentation of spiral threads especially strong on base of body-whorl and with finer interspaced threads particularly prominent there. On later spire-whorls and on body-whorl close below suture is a spiral row of minute elevated tubercles on a somewhat indistinct keel. On the whorls, at the prominent carina at the angle, is a conspicuous spiral band of about 11 sharp nodules merging in earlier spire-whorls into distinct costae which run to the anterior suture.

Besides these two rows of tubercles on the body-whorl are two others—one prominent one on the lower of the carinae of the body-whorl, and a faint one on the base a little below this last. Growth-lines strongly shown and numerous on the body-whorl.

Height, 32 mm.; diameter, 18 mm.

Holotype and two paratypes in author's collection.

Locality: Coast near Kawa Creek, south of Waikato River, Auckland. Collected by Bartrum, 1917.

Remarks.—The late Mr. Suter remarked: “Near S. nodosa (Mart.), but distinguished from it by the row of tubercles below the suture, and a fourth row upon the base. The former character brings it near S. conoidea (Zitt.), from which, however, it is quite distinct.”*

[Footnote] * Personal communication.

– 99 –

Siphonalia kawaensis n. sp. (Plate VII, figs. 9 and 10.)

Three specimens in a moderately good state of preservation; that chosen as holotype is incomplete at the apex of the spire, but shows the aperture and ornamentation well.

Shell oval, of medium size. Spire about half height of shell, angle 55°. Whorls about 8, gradually increasing. Protoconch (shown by a paratype), 2½ smooth whorls.

In ornamentation identical with the preceding species, S. propenodosa, except that the spiral band of nodules on the base of the body-whorl is less distinct. Aperture oval, distinctly notched above, and passing below into a broad short greatly reflected oblique anterior canal, truncated at the base. Columella arcuate above, oblique below. Outer lip thin, sharply angled at upper carina of body-whorl, less so at lower one, somewhat crenulate within. Inner lip very broadly spread over body-whorl as a thick callosity, which is produced into a most conspicuous strong tooth-like process at about the middle height of aperture, just below the band of nodules on the base.

Height, 43 mm.; diameter, 25 mm.

Holotype and two paratypes in author's collection.

Locality: Coast near Kawa Creek, south of Waikato River, Auckland. Collected by Bartrum, 1917.

Spisula aequilateralis gilberti n. var. (Plate VII, fig. 11.)

A very plentiful pelecypod in the Kawa bed, but difficult to collect perfect on account of friability both of fossils and containing beds. Unfortunately the author's specimens were crushed in transit by post from the late Mr. Suter, who examined them, and are not therefore as desirable types as might be obtained.

Shell moderately large, solid, with very heavy hinge with normal dentition and characters. In ornamentation the variety agrees with the normal species, the radial sculpture being perhaps closer and more distinct. In outline and contour there are constant differences. The variety is laterally more compressed, being less globose, and is flattened anteriorly on lower half of valve. The posterior dorsal margin descends rapidly from near the umbo and is straight, the dorsal region much flattened. The anterior dorsal area also is somewhat flatter than in the normal species.

Length, 74 mm.; height, 59 mm.; half diameter, 17.5 mm.

Holotype and imperfect paratype in author's collection.

Locality: West coast, near Kawa Creek, south of Waikato River, Auckland. Collected by Bartrum, 1917.

Terebra benesulcata n. sp. (Plate VII, fig. 12.)

Small, cylindrico-conical shell, with sharp elongate spire. Whorls 7 in the incomplete holotype, rather flattish, gradually increasing; suture rather deep. Spire about 4 times height of aperture. Protoconch absent.

Growth-lines crowded, rather sinuous, specially distinct on penultimate and body whorls. Two spiral rows of strong rounded tubercles, the lower slightly the stronger, with a moderately deep broad sulcus between them, characterize the whorls. Ten tubercles on the penultimate whorl; those of the lower row are continued as low costae to the anterior suture, but on the body-whorl die out before reaching the basal portion. No other spiral sculpture.

– 100 –

Aperture oval, lightly notched posteriorly, and produced anteriorly into a very short widely-open canal sharply bent to the left. Basal margin straight, not notched. Columella fairly short, straight, subvertical. Inner lip thinly and narrowly callous, ending in a point below. Outer lip incomplete. Siphonal fasciole distinct.

Length of imperfect holotype. 9 mm.; diameter, 2.3 mm.

Holotype and two fragmentary paratypes in author's collection.

Locality: West coast, near Kawa Creek, south of Waikato River, Auckland. Collected by Bartrum, 1917.

Tugalia kawaensis n. sp. (Plate VII, fig. 13.)

Small, conical, rounded shell, somewhat produced anteriorly; sub-central, blunt apex, directed back. Posterior slope gentle, straight or only slightly concave, anterior gently convex. Posterior and lateral margins rounded, lateral margins converging towards broadly truncated anterior end.

Slit-fasciole distinctly raised as sharp fold of shell, but not sculpturally differentiated except that it is stronger than adjacent radial riblets. These latter are well developed, about 50 in number, well raised, rounded. Some at intervals better developed than intervening ones; interspaces subequal to ribs. Broad, concentric, rounded ribs, about 8 or 9 in number, are prominent in interspaces, and make the radial ribs themselves slightly nodular; specially prominent in the fragmentary paratype. Towards apex concentric and radial ribs alike diminish.

The interior muscle-scar hooked back anteriorly towards apex.

Length, 6.2 mm.; breadth, 5.3 mm.; height, 2.3 mm.

Holotype and a fragmentary paratype in author's collection.

Locality: West coast, near Kawa Creek, south of Waikato River, Auckland. Collected by Bartrum, 1917.

Turbo postulatus n. sp. (Plate VII, fig. 14.)

Unfortunately only a fragment, comprising little more than the basal portion of the body-whorl, is available for description. It appeared to the writer to represent a species of Turbo previously unknown in the New Zealand fauna, a fact verified by the late Mr. Suter, who declared it to be a new species of that genus.

In spite of the fragmentary nature of the holotype it seems advisable for convenience of reference to give this shell a specific name and to append its description.

Shell fairly large, diameter approximately 27 mm., imperforate; columella mainly straight, highly oblique, but bent to the right near produced basal margin of aperture. Outer lip imperfect, thin; inner lip a widespread thin callosity on body-whorl and the somewhat excavated umbilical region, tapering rapidly to a point below.

Sculpture of body-whorl distinctive: growth-lines very numerous and prominent, crossing several convex, broad, well-raised spiral keels, these latter separated by subequal interspaces. On the indefinitely delimited basal portion of the body-whorl are approximately 4 such keels. The fourth of these is much stronger and broader than the others; it surrounds the relatively depressed umbilical tract and causes a distinct sinuosity of the basal margin of the aperture.

Holotype in author's collection.

Locality: West coast, near Kawa Creek, south of Waikato River, Auckland. Collected by Bartrum, 1917.

Picture icon

Fig. 1.—Bittium, oamaruticum n. sp., 5 mm. × 1.7 mm.
Fig. 2.—Chione auriculata n. sp., 10.6 mm. × 9 mm.
Fig. 3.4.—Circulus cingulatus n. sp., holotype, diam. 4 mm.
Fig. 5.—Racta tenuiplicata n. sp., holotype, 37 mm. × 32
Fig. 6.—Rasta tenuiplicata n. sp., paratype.
Fig. 7.—Siphonalia propenodosa n. sp., paratype.
Fig. 8.—Siphonalia propenodosa n. sp., holotype, 32 mm. × 18 mm. Fig. 9.—Siphonalia kawaensis n. sp., holotype, 43 mm. × 25 mm.
Fig. 10.—Siphonalia kawaensis n. sp., paratype.
Fig. 11.—Spisula aequilateralis gilberti n. var., holotype, 74 mm. × 59 mm.
Fig. 12.—Terebra benesulcata n. sp., 9 mm. ×; 2.3 mm.
Fig. 13.—Tugalia kawaensis n. sp., 6.2 mm. ×; 5.3 mm.
Fig. 14.—Turbo postulatus n. sp., diam. approx. 27 mm.