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Volume 23, 1890
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Art. IX.—Descriptions of New Species of New Zealand Land and Fresh-water Shells.

Communicated by the Secretary.

[Read before the Philosophical Institute of Canterbury, 6th November, 1890.]

Plates XVI.-XVIII.

Rhytida meesoni, n. sp. Plate XVI., fig. 1, a, b, A.

Shell subdiscoidal, depressed, umbilicated, horny with a greenish hue at the base, shining, thin and fragile, transparent, epidermis with fine growth-lines, slightly wrinkled and malleated. Spire flat. Whorls 3, slightly convex, rapidly increasing, periphery rounded, the last somewhat deflexed anteriorly. Suture not deep. Aperture obliquely lunate-oval. Peristome simple, acute, margins approximating and joined by a faint callus. Columellar margin arched, reflexed at the upper part, slightly callous. Umbilicus moderate deep, open, about one-sixth of the diameter.

Diameter, 0.45in. (11.5mm.); height, 0.24in. (6mm.). The largest specimen I have seen measured 0.5in. by 0.26in.

Hab. South Island: Wairoa Gorge, near Nelson (J. T. Meeson).

Named in honour of Mr. J. T. Meeson, of Christchurch, to whom we are indebted for this addition to our land-shells.

Animal.—Amongst the specimens Mr. Meeson kindly gave me there were some in which the dried-up animal was left, and of those I succeeded in preparing the radula.

Jaw none.

Dentition: 12—0—12. Transverse rows of teeth forming an acute angle. Teeth slender, aculeate, increasing from the centre up to the 10th, which is the largest. The 11th is not half as long, and the last rudimentary, not found on the posterior part of the radula. The 10th tooth has an angular ridge; all the others are smooth.

Patula mutabilis, n. sp. Plate XVI., fig. 2, a, b, B, C.

Shell subdiscoidal, depressed, umbilicated, white, sometimes horny, irregularly streaked with rufous, but the white form seems to be predominant; faintly shining, rather thin, transparent; with sharp, rather distant arcuated plaits, directed strongly forwards on the surface, slightly undulating on the side, the interstices with numerous fine growth-lines. Ribs about 13 in the tenth of an inch (5 per mm.). Spire slightly elevated, flat. Whorls 5 ½, narrowly rolled up,

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very slowly increasing, rounded, the last not descending. Suture deep. Aperture slightly oblique, rotundly-lunar somewhat excavated by the penultimate whorl. Peristome straight, acute, tapering; columellar margin straight, not reflected. Umbilicus broad, perspective, showing all the whorls, about one-third of the diameter.

Diameter, 0.12in. (3mm.); height, 0.06in. (1.5mm.).

Hab. Under rotten wood, dead leaves, and amongst mould in the subalpine bush. Very scarce. South Island: White Horse Hill, and foot of Sealy Range, Hooker Valley. (H. S.)

This species seems to be closely allied to Helix eastbournensis, Beddome and Petterd, from Tasmania, but in the latter the ribs on the upper surface are nearly straight, not arcuated; the spire is more elevated and not flat, and the umbilicus rather narrower and deeper. But there also occurs a perfectly white and a darker streaked form.

Animal.—Jaw finely striated, arcuated, not tapering, with a slight median projection.

Dentition: 16—1—16; laterals, about 7. Central tooth rectangular, longer than broad, the reflexed portion tricuspid, covering about one-third of the base, sides concave, median cusp as long as the base, with a moderate cutting-point, lateral cusps small. Laterals much the same as the central tooth. The first marginals with an oblique reflexed portion and three cutting-points, the outer ones rectangular, much broader than long, some of them with four cutting-points, the last very minute, toothless.

Patula sterkiana, n. sp. Plate XVI., fig. 3, a, b, D, E.

Shell subdiscoidal, depressed, umbilicated, grey-yellowish with very irregular rufous streaks and dots, sometimes tessellated or forming zig-zag lines; not shining, rather solid, transparent; with very fine rib-like arcuated striæ, directed forwards on the surface, undulating on the side and straight beneath. Ribs about 60 in the tenth of an inch (24 per mm.). Spire but little elevated, flat. Whorls 5 ½ to 6, slowly increasing, rounded, the last slightly descending. Suture rather deep. Aperture oblique, lunately subcircular, but little excavated by the penultimate whorl. Peristome straight, acute, tapering, margins slightly convergent, columellar margin arcuated, very little expanded. Umbilicus moderate, deep, about one-fourth of the diameter.

Diameter, 0.16in. (4mm.); height, 0.08in. (2mm.).

Hab. Under dead leaves and rotten wood in the sub alpine bush. South Island: White Horse Hill, Hooker Valley. (H.S.)

This species is, in the form of the shell, allied to Patula tapirina and P. infecta, but is much closer ribbed.

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Named in honour of my friend Dr. Sterki, New Philadelphia, Ohio.

Animal.—Jaw arcuated, not tapering, finely striated, with a slight median projection.

Dentition: 16—1—16; laterals, 4. Central tooth rectangular, not much longer than broad; the reflexed portion tricuspid, the side cusps short, middle cusp with the cutting-point reaching to the posterior margin. Laterals much like the central. Marginals tricuspid, the reflexed portion oblique on the inner ones, the outer ones much broader than long, the last small, bicuspid.

Patula brouni, n. sp. Plate XVI., fig. 4, a, b, F, G.

Shell minute, subdiscoidal, umbilicated, pale-horny with rather distant dark-horny streaks, forming zig-zag lines on the periphery and beneath; not shining, thin and fragile, transparent; with very fine and close ribs, nearly straight and directed forwards on the surface, straight on the side and at the base; about 60 in the tenth of an inch (24 per mm.). Spire scarcely reaching above the last whorl. Whorls 5, narrowly rolled up, slowly increasing, rounded, the last not descending. Suture impressed. Aperture slightly oblique, rotundly lunar, but little excavated by the penultimate whorl. Margins regularly arched, convergent, straight, acute, the outer lip slightly advancing. Columellar margin short, arcuated, not reflected. Umbilicus broad, perspective, one-third of the diameter.

Diameter, 0.09in. (2.25mm.); length, 0.04in. (1mm.).

Hab. Under decaying leaves and amongst mould in the subalpine bush. South Island: White Horse Hill, Hooker Valley. (H. S.)

Named in honour of Captain Thomas Broun, of Karaka, Drury.

This shell is closely allied to Pat. sterkiana, and has the same fine ribs, but may at once be distinguished from it by its smaller size, the different markings, and the somewhat different course the ribs take.

Animal.—Jaw very thin, arcuated, finely striated, not tapering, with a slight median projection.

Dentition: 14—1—14; laterals, 4. Central tooth rectangular, longer than broad, reflexed portion tricuspid, the central cusp long, reaching almost to the posterior margin of the base, with a short cutting-point. First two laterals much the same as the central tooth, the other two with longer cutting-points. Marginals with the base much broader than long, with three long cutting-points; the last rudimentary, minute, unicuspid.

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Patula serpentinula, n. sp. Plate XVI., fig. 5, a, b, H, J.

Shell small, subdiscoidal, umbilicated, pale-horny with regular streaks and dots of rufous; not shining, thin, transparent; with sharp close-set ribs, arcuated, and directed for wards on the surface, sinuated at the periphery and straight beneath; about 38 in the tenth of an inch (15 per mm.). Spire scarcely elevated. Whorls 5, rather narrow, regularly increasing, slightly rounded, the last not descending. Suture deep. Aperture subvertical, rotundly lunar, very little excavated by the penultimate whorl. Peristome simple, straight, the upper margin slightly advancing, margins convergent. Columellar margin short, arcuated, not reflexed. Umbilicus large, perspective, showing all the whorls, one-third of the diameter.

Diameter, 0.1in. (2.5mm.); height, 0.05in. (1.25mm.).

Hab. Under rotten wood and decaying leaves in the sub-alpine bush. South Island: White Horse Hill, Hooker Valley. (H. S.)

This shell is near Patula sterkiana and P. brouni, but the ribs are more distant. It is finer ribbed than Patula infecta.

Animal.—Jaw arcuate, faintly striated, very thin, no median projection.

Dentition: 11—1—11; laterals, 5. Central tooth rectangular, not much longer than broad, reflexed portion tricuspid, the central cusp long, reaching nearly the posterior margin of the base, all the three cutting-points short. Laterals very much like the central tooth, but almost quadrate. Marginals much broader than long, with three to four cutting-points, of which the two inner ones are stouter and longer; the last marginal minute, quadrate, unicuspid.

Patula eremita, n. sp. Plate XVII., fig. 6, a, b.

Shell very minute, subdiscoidal, umbilicated, pale-horny with faint broad streaks of darker horny, silky, fragile, transparent; with fine and numerous ribs, slightly arcuated and directed forwards on the surface, straight on the side and beneath; about 70 in the tenth of an inch (28 per mm.). Spire minute. Whorls 4 ½, narrowly rolled up, regularly but slowly increasing, rounded, the last not descending. Suture deep Aperture subvertical, rotundly lunate, but little excavated by the penultimate whorl. Peristome straight, acute, regularly arched, margins convergent. Columellar margin short arcuated, not reflected. Umbilicus broad, perspective, about one-third of the diameter.

Diameter, 0.08in. (2mm.); height, 0.03in. (0.75mm.).

Hab. Under decaying leaves in the subalpine bush. Exceedingly

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scarce (one specimen only). South Island: White Horse Hill, Hooker Valley. (H. S.)

This shell represents a middle form between Patula infecta and P. corniculum.

Animal not known, as I would not destroy the only specimen I have.

Patula infecta, Reeve, var. alpestris, n. var.

The shell of this variety differs from P. infecta, R., by its different colour, it being cinereous-rufous with only a few pale-horny streaks. The ribs are stouter and more distant, about 18 in the tenth of an inch (7 per mm.). The whorls number only 4 ½ to 5; they are somewhat broader, less rounded, and the suture, in consequence, less impressed. The peristome has no callosity inside.

Diameter, 0.12in. (3mm.); height, 0.06in. (1.5mm.).

Hab. Amongst decaying leaves in the subalpine bush. Scarce. South Island: White Horse Hill, Hooker Valley. (H. S.)

Animal unknown.

Patula bianca, Hutt., var. montana, n. var. Plate XVII., fig. K, L.

Shell differs from the type by its larger size, by the darker colour, this being fuscous without any streaks, and the coarser and more distant ribs, there being only about 35 in the tenth of an inch (14 per mm.).

Diameter, 0.11in. (2.75mm.); height, 0.05in. (1.25mm.).

Hab. Under rotten wood and dead leaves in the subalpine bush. South Island: White Horse Hill, Hooker Valley. (H. S.)

Patula bianca, Hutt., is also found in the same locality, but rather scantily, and it differs a little from the type by the diameter being never over 0.08in. (2mm.), by having four whorls, and by the ribs being more distant, about 50 instead of 55 in the tenth of an inch.

Animal.—Jaw very thin, almost straight, not tapering, faintly striated, no median projection.

Dentition: 13—1—13; laterals, 4 or 5. Central tooth rectangular, longer than broad, reflexed portion tricuspid, middle cusp reaching about two-thirds of the length of the base, all the cutting-points short. Laterals a little broader than the central tooth, but similar in shape, the middle cusp with its short cutting-point reaching to the posterior margin of the base. Marginals much broader than long, especially the outer ones; with three stout cutting-points, of which the two inner ones are more developed. Last marginal minute, bidentate.

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Patula corniculum, Reeve, var. maculata, n. var.

Shell agrees in almost every respect with the type of the species, but the white epidermis is adorned with rufous radiate streaks at very irregular distances and from narrow to broad. There are about 50 ribs in the tenth of an inch (20 per mm.), whilst the species, according to Professor Hutton, has only 40; but I do not think this to be of much value for distinguishing the variety. According to my observations Pat. corniculum varies considerably in the number of the ribs in different localities. I collected specimens in the Forty-mile Bush with about 50 ribs in the tenth of an inch, and near Wellington with less than 40.

Diameter, 0.11in. (2.75mm.); height, 0.06in. (1.5mm.).

Hab. Amongst decaying leaves in the subalpine bush; very scarce. South Island: Foot of Sealy Range, Hooker Valley. (H. S.)

Animal unknown.

Pitys cryptobidens, n. sp. Plate, XVII., fig. 7, a, b, c, M, N.

Shell very minute, discoidal, umbilicated, cinereous, not shining, very fragile, subtransparent, with very fine and extremely close-set ribs, which are slightly bent forwards, but almost straight on the surface, and rather sinuated at the periphery, about 85 to 90 in the tenth of an inch (35 per mm.). Spire flat. Whorls 4 ½, narrow, rounded, regularly increasing, the last not descending. Suture deep. Aperture rotundly lunate, subvertical, slightly excavated by the penultimate whorl. Peristome acute, somewhat flattened at the base, the upper margin advancing. Interior of the aperture with two teeth. There is a callosity on the basal margin, from which to the left rises a stout conical tooth; another tooth of the same shape is near the middle of the parietal wall. Both teeth are at some distance from the margin. Columellar margin short, arcuated, slightly reflected. Umbilicus broad, perspective, showing all the whorls, about one-third of the diameter.

Diameter, 0.07in. (1.75mm.); height, 0.03in. (0.75mm.).

Hab. Amongst mould in the subalpine bush; very scarce (three specimens found only!). South Island: White Horse Hill, Hooker Valley. (H. S.)

Animal.—As I had only three specimens, I would not sacrifice more than one for preparing the jaw and radula. As the animals were dried up in their shells this proved to be a most difficult task, considering the minuteness of the objects. The animal was soaked for a long time in water, then in glycerine, and repeatedly treated with caustic potash, but it was impossible to prepare the radula in a perfectly good condition, and, owing to the great brittleness, I dared hardly touch it

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with a needle, and had to leave it partly rolled up. Nevertheless I succeeded in seeing some of the teeth perfectly well, but I am unable to say what is their number.

Jaw oxygnath, tapering, with a narrow lamella in the middle.

Dentition: Central tooth quadrate, the reflexed portion tricuspid, the middle cusp with its short cutting-point reaching to the end of the base; there are three or four laterals exactly of the same form, and then follow some laterals with the base much broader than long and three equal cutting-points. The marginals are bicuspid and acuminate.

Mr. Harper Pease has given the name of Pitys to a group of Patula-like Polynesian shells, some of which have their aperture adorned with laminæ, whilst others are without. To the latter ones Professor A. Mousson, in his collection, has given the name of Simplicaria. Most of the conchologists consider Pitys to form a group of the genus Patula, or a genus of the family of the Patulidæ.

I think I am right in referring our shell to Pitys. To my knowledge there is no other group or genus in which it could be placed at present. But the jaw and the dentition show clearly that it does not belong to Patula or the Patulidæ. Its place is in the family of the Limacidæ. I never had an opportunity of examining the dentition of a Polynesian Pitys, and I do not know whether it has ever been done or not. The anatomical study of these molluscs would be of great interest and value, and would furnish the necessary basis for a correct classification. It is rather astonishing what a large number of very different forms are now included in one group or sub-genus, such as Charopa, Endodonta (including Pitys), and many others. It is only by way of anatomical examination that light can be brought into this chaos.

It is the first time a Pitys with lamellæ has been found in New Zealand, and I think it to be of great value, as it gives an additional proof of our former land-communication with a part of Polynesia.

Psyra godeti, n. sp. Plate XVII., fig. 8, a, b, O, P.

Shell discoidal, perforated, colour horny without any markings, not shining, transparent, thin, with strong, rather distant, and almost straight radiate ribs, about 23 in the tenth of an inch (9 per mm.). Spire flat. Whorls 5, slightly rounded, narrow, regularly increasing, the last not descending. Suture impressed. Aperture subvertical, lunar, considerably excavated by the penultimate whorl. Peristome straight, simple, basal margin slightly arcuated. Columellar margin very short, but little reflected, slightly thickened. Umbilicus very narrow, but open.

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Diameter, 0.18in. (4.5mm.); height, 0.1in. (2.5mm.).

Hab. Under stones. South Island: Foot of Sealy Range, Hooker Valley. (H. S.)

Our species stands nearest to Psyra tullia, Gray, but is easily distinguished from it by the absence of any markings, the stronger and more distant ribs, and the open umbilicus.

Named in honour of Professor Paul Godet, in Neuchatel, Switzerland.

Animal.—Jaw slightly arcuate, not tapering, flatly ribbed, the ribs indenting the convex margin.

Dentition: 20—1—20; laterals, 6. Central tooth rectangular, not much longer than broad, reflexed portion tricuspid, the central cusp with the cutting-point reaching the posterior margin of the base. Laterals a little broader than the central tooth, bicuspid, the inner cutting-point long, reaching beyond the base. Marginals much broader than long, with four to five cutting-points, the last minute, denticulated. The larger cutting-points of the laterals and marginals reach over the next row of teeth.

Amphidoxa (Calymna) feredayi, n. sp. Plate XVIII., fig. 10, a, b, Q, R.

Shell small, globosely depressed, imperforate, shining, pale-horny, without markings, thin, transparent; with fine ribs, arcuated on the surface and disappearing beneath, about 25 to 30 in the tenth of an inch (10–12 per mm.). Spire short, obtuse. Whorls 3 ½, rapidly increasing, rounded. Suture impressed. Aperture oblique, rotundly-ovate. Peristome thin, straight, regularly arched, the upper part advancing. Columellar margin somewhat bent to the left, not reflexed. Margins approximating. Umbilical region infundibuliform, imperforate.

Diameter, 0.14in. (3.5mm.); height, 0.08in. (2mm.).

Hab. Under rotten wood in the bush; very scarce. North Island: Hastwell, Forty-mile Bush. (H. S.)

Named in honour of Mr. R. W. Fereday, of Christ-church.

Animal long, slender, yellowish-grey with fine black spots. Eye-peduncles black, rather stout, slightly clavate; eyes large. A streak on each side of the head black. Mantle sub-central, whitish. Foot 4mm. long, sole separated by a furrow. Tail acutely rounded. Caudal slit (?).

Jaw arcuated, tapering, stegognath, consisting of numerous parallel lamellæ.

Dentition: 20—1—20; laterals, 7. Central tooth rectangular, longer than broad, the reflexed portion tricuspid, the apical cutting-point as long as the base, the cuspids on the convex sides short. Laterals nearly like the central tooth.

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Marginals quadrangular, broader than long, with three cutting-points, the last only with a cutting-edge, sometimes without it.

Amphidoxa (Calymna) feredayi, Sut., var. glacialis, n. var.

Shell small, globosely depressed, imperforate, silky, pale-horny without markings, fragile, transparent, with very fine, distinct, and close striæ, arcuated on the surface and straight beneath, about 60 in the tenth of an inch (25 per mm.). Spire almost flat. Whorls 3 ½, rapidly increasing, rounded. Suture impressed. Aperture oblique, rotundly ovate. Peristome thin, regularly arched, the upper part of the outer lip advancing. Columellar margin not reflected. Margins slightly con-vergent. Umbilical region impressed, imperforate.

Diameter, 0.14in. (3.5mm.); height, 0.07in. (1.75mm.).

Hab. Under rotten wood in the subalpine bush; very scarce. South Island: White Horse Hill, Hooker Valley. (H. S.)

Animal.—Jaw and dentition much the same as in the species.

This variety differs from the species only in the closer ribs and the somewhat less elevated spire.

Phrixgnathus acanthinulopsis, n. sp. Plate XVIII., fig. 11, a, b, S, T.

Shell small, conoidal, umbilicated; colour pale-horny with regular broad streaks of rufous, faintly shining, transparent, fragile. Epidermis with slightly-sinuated membranaceous plaits, about 12 in the tenth of an inch (5 per mm.). Spire conoidal, rather depressed. Whorls 5, slowly but regularly increasing, rounded; periphery carinated. Suture impressed. Aperture oblique, rotundly lunar. Peristome thin, straight, the margins slightly approximating. The columellar margin scarcely reflected, somewhat callous inside. Umbilicus moderate, deep, open, one-fourth of the diameter.

Diameter, 0.12in. (3mm.); height, 0.08in. (2mm.).

Hab. Amongst dead leaves and mould in the subalpine bush. Rather scarce. South Island: White Horse Hill, Hooker Valley. (H. S.)

This species is very near Ph. phrynia, Hutt., but the spire is more depressed and the umbilicus larger.

Animal.—Jaw arcuate, not tapering, lamellate, the lamellæ flat, densely covered with hair-like papillæ; about five of the central lamellæ much broader than the others.

Dentition: 21—1—21. Central tooth rectangular, much longer than broad, reflexed portion nearly half the length of the base, unicuspid, marginal teeth twice as broad as the central tooth, bicuspid, the cutting-points growing larger and

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reaching the posterior margin of the base as they approach the margin of the radula. The last two teeth much broader than long, with rudimentary cusps.

Amphipeplea ampulla, Hutt., var. globosa, n. var. Plate XVIII., fig. 12,a, b, c.

Shell ovate, inflated, very thin and fragile, pale-horny, faintly shining, transparent, longitudinally plaited, plaits close-set and well marked. Spire short, acute, apex sometimes eroded. Whorls 4, the last inflated. Suture impressed. Aperture large, ovate, occupying about three-quarters of the length of the shell; the outer lip not reflected, thin and sharp; inner lip very broadly reflected, covering the umbilicus. Columella arcuate, with a spiral fold.

Dimensions: Length, 0.5in. (13mm.); breadth, 0.35in. (9mm.). Aperture: Length, 0.39in. (10mm.); breadth, 0.24in. (6mm.). The measures given are those for perfectly adult specimens.

Hab. South Island: Birch Hill Lagoon, Tasman Valley. (H. S.)

The animal is the same as in the species, and in the dentition there is not such a difference as to justify the creation of a new species. Professor F. W. Hutton kindly gave me some specimens of his A. ampulla, and I have thus been able to compare the radulæ.

The shell differs from A. ampulla by the more globular form, the larger size, the lighter colour, and the more considerable fragility and transparency. The spire is, as a rule, somewhat shorter, and the reflexed portion of inner lip broader.

This is a very variable shell, but adult specimens are always much more inflated than any A. ampulla I have seen.

[For explanation of Plates XVI.-XVIII., see end of Article X.]