Go to National Library of New Zealand Te Puna Mātauranga o Aotearoa
Volume 15, 1882
Previous Article | Table of Contents | Next Article
This text is also available in PDF
(576 KB) Opens in new window
– 87 –

Plate IV.
Corrections and Additions to previous Paper. *

In my previous paper I have stated that the well from which the Crustacea were obtained was “not more than twenty-five feet deep.” I have since found that this is considerably too much, it is really only sixteen or seventeen feet deep; since then, however, the well has been filled in, so that it is now practically the same as though the pipe had been simply driven into the ground as in an artesian well.

The Crustacea still continue to come up, though not so frequently as before, and they now vary more, sometimes coming up pretty abundantly while at other times they are very scarce; and while previously Calliope subterranea (female) used to be much more abundant than any of the other species, it now, though still more abundant than the others, does not preponderate over them nearly so much as before. Next come Crangonyx compactus and Cruregens fontanus which occur in about equal numbers, while Gammarus fragilis is now the rarest of all.

From another pump about two or three chains from the first, I have obtained a few specimens of Calliope subterranea (female), and from a third pump about a mile and a half distant I got a single specimen of Gammarus fragilis, and I have heard of similar animals being seen from another pump about a mile distant from the first one, but I have not seen specimens from this well. These facts seem to show that the Subterranean Crustacea are fairly well distributed in the district.

All these wells are sunk in a bed of gravel which lies immediately under the surface soil. Through this gravel water continually percolates, and can always be found at the depth of a few feet from the surface, the depth varying according to the situation, the dryness of the season, the state of the neighbouring River Eyre, etc. I do not think that there is anywhere any large connected quantity of water, but I believe that the Crustacea live in the water which percolates through the interstices between the stones in the bed of gravel.

With regard to the origin of these Crustacea one can as yet only conjecture. Their nearest allies appear to be marine in their habitat. Cruregens fontanus would, but for the absence of the last pair of thoracic legs, come under the genus Paranthura, the species of which, as well as of the allied genus Anthura, are all marine. Besides Cruregens fontanus, I have obtained

[Footnote] * “On some Subterranean Crustacea,” “Trans. N.Z. Inst.,” vol. xiv., p. 174.

– 88 –

another Isopod (described in the latter part of the paper) whose nearest allies are marine. Calliope subterranea is inconclusive, for we have in New Zealand one marine and one fresh-water species; it is, however, not at all near to C. fluviatilis the fresh-water species, and certainly has not arisen out of that species.

Gammarus fragilis, again, does not prove anything, for though in New Zealand we have only one species, a marine one, in Europe some species are marine and some fresh-water. The genus Crangonyx contains only two species besides C. compactus, mihi, one C. subterraneus from a well in England, the other C. ermanni from warm springs in Kamschatka; its nearest allied form, however, is a marine genus, Gammarella.

On the whole, both the Isopoda and the Amphipoda are so distinctly marine and their fresh-water representatives in New Zealand so few, in fact only two, Calliope fluviatilis and Idotea lacustris, that it is difficult to believe that the subterranean fauna, which, so far as at present known, contains five species, could have arisen from any other than the marine fauna.

Cruregens fontanus.—Since writing my previous paper I have obtained a great number of specimens of this species—between 40 and 50—and they all agree in having the last thoracic segment small and without appendages, so that there can no longer be any doubt that the form I have described is the adult form.

In living specimens the heart can be distinctly seen through the transparent integument. It is elongated and extends from the middle of the fifth abdominal segment anteriorly, reaching nearly to the middle of the sixth thoracic segment. The anterior end of the heart is narrower than the posterior part, and the posterior end is rounded. There appear to be three openings through which blood flows into the heart; one is on the left side in the second abdominal segment; the other two are on the right side, one in the seventh (last) thoracic segment, and the other in the third abdominal segment. These openings appear to be provided with valves of some kind. Blood passes out through the anterior end of the heart, in the median line of the body, and flows forwards to supply the various parts of the body.

In my previous paper I have stated that the only blind Isopoda inhabiting wells or caves that I could find mention of were two species of a genus, Cœcidotea, found in the Mammoth Cave of Kentucky and in the Wyandotte Cave; since then I have found two others mentioned, but I have not been able to get descriptions of them; they are Titanethes albus, Schiödte, which inhabits caves of Carniola* and Typhloniscus steinii.†

[Footnote] * See “Nature,” 18th April, 1872, p. 484.

[Footnote] † See “Trans. Linn. Soc.,” 2nd ser., vol. I., pt. i., p. 24 (footnote). Others are mentioned in the Zoological Records for 1879 and 1880.

– 89 –

I have now to add another obtained from the same well as the other Subterranean Crustacea that I have described.

Previous Article | Table of Contents | Next Article