Art. XXII.—Notes on New Zealand Land Planarians: Part II.*
[Read before the Philosophical Institute of Canterbury, 3rd July, 1895.]
The present contribution to our knowledge of the land planarians of New Zealand deals exclusively with a number of specimens collected during a month's stay at Springburn, at the foot of Mount Somers, in November and the early part of December of last year (1894). In the immediate vicinity of the thick bush-scrub of the Alford Forest the locality appeared a good hunting-ground for cryptozoic animals, and experience showed that this was indeed the case. The very luxuriance of the vegetation, however, with its unlimited hiding-places for cryptozoic animals, made the task of collection more difficult than it would have been in a clearer neighbourhood, where the animals are concentrated, as it were, in a comparatively few spots.
[Footnote] * For Part I. see Trans. N.Z. Inst., vol. xxvii., art. xvii.
The majority of the species collected have already been described in the first part of these notes, but even concerning these a certain amount of additional information was obtained.
Geoplana triangulata, var. australis, Dendy.
This large, handsome variety was met with in abundance, being perhaps the commonest form in the locality. The colour of the dorsal surface was usually dark-purplish-brown in its median portion, while the margins and ventral surface ranged from pale-yellow to orange. Some specimens were found associated with dead beech-leaves, which, in their two prevailing shades of orange and dark-brown, almost exactly matched the colours of the planarians. Possibly we have here a case of protective resemblance. It is interesting to note that all the specimens found were without the dark speckling on the margins and ventral surface. Thus they agree with the Dunedin form. In Christchurch, on the other hand, none but the speckled form has yet been found, though the species is very common.
Geoplana latissima, n. sp.
When at rest, very broad and short, flattened, not triangular in section; when crawling, long and narrow, strongly convex above, flat beneath. Length of a specimen when crawling, 62mm.; breadth of another at rest, 11mm. Eyes small and rather few, arranged in almost single series around the anterior extremity.
Dorsal surface orange, shading into pinkish anterior tip, and with narrow yellow margins. A very narrow deeper-orange stripe may be visible in the mid-dorsal line in the posterior part of the body. Ventral surface very pale yellow, nearly white, without markings.
In spirit the shape of the body is very characteristic—very short and broad, and with the two ends curled in ventrally. The anterior end is bluntly pointed, hollowed underneath and convex above. The posterior end is much more bluntly rounded off, and has a slight median notch in the margin (present in four out of five specimens, the other being injured posteriorly). The very narrow lateral margins are thin and prominent, and slightly upturned. Both apertures are situate far back, the peripharyngeal at about the junction of the middle and posterior thirds, and the genital perhaps slightly nearer to it than to the posterior extremity.
At first sight this species resembles Geoplana triangulata, var. australis, but in life the orange colour is really very characteristic, while in spirit the shape of the body is still more so. It is the broadest land planarian in proportion to
its length which I have seen, the length in spirit being scarcely more than twice the breadth.
Geoplana alfordensis, n. sp.
When crawling, long and narrow, convex above and flattened below. One specimen measured, when crawling, about 33mm. in length by 2mm. in breadth. The ground-colour of the dorsal surface is very pale yellow, with a pair of rather broad dark-reddish or chestnut-brown stripes. The width of the median band of ground-colour varies a good deal in the three specimens. Anterior tip pink. Ventral surface very pale yellow, without markings. Eyes as usual, but comparatively few and inconspicuous.
In spirit the body is of approximately uniform width, except where it tapers just at the anterior and posterior extremities. It is oval in transverse section, convex dorsally and ventrally, and with rather prominent lateral margins. The peripharyngeal aperture is well behind the middle of the body. The position of the genital was not very satisfactorily determined.
Geoplana purpurea, Dendy.
I identify four specimens as a slight colour variety of this species. The colour in life was very dark brown, nearly black, on the dorsal surface, with narrow dirty-white median stripe. The ventral surface was lighter brown, and the anterior tip pale-brownish.
Geoplana quinquelineata, Fletcher and Hamilton.
I identify with this common Australian species two small specimens. The largest was only about 30mm. long when crawling. At rest, flattened on both surfaces, but not markedly quadrangular. Ground-colour very pale yellow all over, with five dark-grey stripes on the dorsal surface, the median one narrowest. Anterior tip pink.
Geoplana graffii, Dendy.
Three fairly typical, although rather small, examples of this species were met with.
Geoplana graffii, var. somersii, nov.
This variety, represented by three specimens, differs from the typical form in the suppression of the pale longitudinal bands on both surfaces. The body in spirit also appears to be narrower in proportion to its length, and hence less leaf-like. The colour is greyish-brown all over, with minute white specks; paler on the ventral surface, but also speckled. The white specks or dashes are more strongly developed in the mid-dorsal line than elsewhere, perhaps indicating the lost
median stripe. The peripharyngeal aperture in spirit is some what behind the middle, and the genital rather nearer to it than the posterior extremity.
Geoplana iris, n. sp.
Closely resembling G. graffii, to which it is evidently nearly allied, in size and shape and in the general markings of the dorsal surface, but differing strikingly in the details of pattern. In the mid-dorsal line is a rather narrow pale band of brownish yellow or orange, sometimes edged with iridescent green. On each side of this is a broad band of dark chocolate-brown, in all specimens edged on the outside with iridescent blue, and about twice the width of the median band. This is followed again by a narrow marginal band of orange, which may also have greenish iridescence on its outer edge. The ventral surface is pale, dull orange, without markings. The anterior tip is dull-orange or dark pinkish-brown. The peripharyngeal aperture is decidedly behind the middle, and the genital about half-way between it and the posterior end.
Geoplana inæqualistriata, Dendy.
This species was originally described from a single specimen found crawling on an asphalt path near Christchurch, and it therefore gives me peculiar satisfaction to be able to record the discovery of a fine specimen in its native haunts, beneath a rotten log near the edge of the Alford Forest.
When at rest it was broad and flattened; when crawling, long but fairly broad, broader behind than in front, strongly convex above, flattened or concave below, measuring about 80mm. by 5mm. Dorsal surface brownish-grey with white stripe and dashes arranged exactly as in the type. Ventral surface white, with abundant small brownish-grey specks, which are absent from the prominent narrow margins, and almost absent from a narrow median band. Anterior tip pink. Eyes as usual. In spirit the body contracts but little. The ventral surface is slightly concave, with very prominent margins, the dorsal surface convex. The peripharyngeal aperture is situate decidedly behind the middle, but well in the middle third, and the genital aperture is at about one-third of the distance from it to the posterior end. The white markings became, in parts, distinctly yellow in spirit.
[Since the above was written I have found, on 30th June, another specimen of G. inæqualistriata in my garden at St. Albans, where the type specimen was obtained. The last-found specimen was lying under a large stone. I placed it in a tin collecting-box with some parsley leaves and left it on the verandah, intending to preserve it in spirit next day. There
was, however, a severe frost in the night, and the animal was dead and liquefying the next morning.]
Geoplana subquadrangulata, Dendy.
This common species is represented in the Springburn district by two varieties:—
(a.) Has the three dark stripes on the dorsal surface as usual, with abundant dark speckles between the median and paired stripes. The lateral surfaces also have numerous dark speckles, concentrated so as to form a discontinuous lateral stripe. The ventral surface is without speckles.
(b.) Is remarkable for the great breadth of the paired dorsal stripes, which extend inwards until they are separated from the median narrow stripe by only a very narrow band of ground-colour. The ground-colour is very pale yellow, the stripes dark-grey or olive-brown. The lateral surfaces are slightly speckled with grey; the ventral surface is not speckled.
Several specimens of each variety were met with.
Geoplana mariæ, Dendy.
This species, which was originally described from a single specimen from near the Otira Gorge, was not uncommon at Springburn. Its most striking characteristic is the shape of the body in spirit—very thick, strongly convex on both surfaces, and very blunt at both ends. Most, if not all, of the Springburn specimens exhibit a paler band at the junction of the dorsal and ventral surfaces. In my first description I compared the shape of the body to that of G. fletcheri, but this is a mistake, as it is really very different, especially in spirit. In the markedly posterior position of the apertures, however, there is a real resemblance between the two.