Art. XII.—Report on Sundry Invertebrates from the Kermadec Islands.

By Professor Benham, D.Sc., F.R.S., Otago University.

Velella cyanea Lesson.

Lesson, Voy. de “Coquille,” vol. 2, pt. 2, chap. 15, p. 54; Zoophytes, pl. 6, figs. 3, 4. Haeckel, “Challenger” Reports, 28, p. 83.

This common Pacific species was cast ashore on Denham Bay.

Class Scyphozoa.

? Atolla sp.

A single somewhat torn and distorted specimen, measuring 30 mm. in diameter, with a height of 15 mm. in the centre of the umbrella, was found on the shore of Sunday Island. It was so much injured that I am not quite sure even of the genus; but it agrees in so many features with Atolla that I have but little hesitation in placing it here. I will not, however, attempt to give a specific name to it.

Class Holothuroidea.

Actinopyga (Muelleria) parvula Selenka.

M. flavo-castanea Theel: Selenka, Zeit. Wiss. Zool., 17, 1867. “Challenger” Reports, Holothuroidea, pt. 2, p. 198, 1886.

[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]

Fifteen specimens were sent to me. Oliver notes that the “colour is dark brown to nearly black: common at Coral Bay, under stones near low-water mark; not seen elsewhere.” In alcohol it is chocolate-brown with a purplish hue. The majority are uniformly coloured, darker dorsally and only slightly paler ventrally; but in four individuals there is an abrupt transverse line separating the dark anterior region from a posterior paler region. In one specimen the change occurs at about ⅗ of its length from the anterior end, in two others at ¾, and in one at 1/7; of the length. From the condition of the ventral ambulacra it appears that this hinder end has been regenerated, for here the podia are in distinct narrow lines, whereas in the normal darker part of the body these organs spread out into the interambulacra, where there are about 15 in a transverse line, instead of only 2 to each ambulacrum. There is, too, a transition observable as the ambulacra are traced forwards, indicating a gradual resumption of the adult condition.

Distribution.—Bedford, in his report on the Funafuti Holothurians, speaks of this species as “the most widely distributed circumtropical species of the genus.”

Chirodota rigida Semper.

Semper, Reisen im Archipel der Philippinen, Holothurien, p. 18, pl. 3, fig. 3; pl. 5, figs. 3, 13, 1868. Lyman Clark, “The Apodous Holothurians,” p. 117, 1907.

The wheels differ from those figured, in that there is a distinct constriction of the radii at their junction with the rim; but, as my specimens agree in the general characters of the species, I have little doubt that this is the correct determination. Oliver states that the “general colour is reddish-purple; it occurs in sand and mud under stones in rock-pools and at low-water mark. It is not common.”

Loc.—Meyer Island.

Distribution.—Clark says it is “apparently well distributed through the entire East Indian region.”

Class Sipunculoidea.

Sipunculus nudus Linnaeus.

This Mediterranean species is widely distributed; it has been recorded from Singapore, Japan, and elsewhere.

Loc.—Sunday Island.

Collected by Mr. R. S. Bell.

Physcosoma scolops. Selenka and Man.

Phascolosoma annulata Hutton, Trans. N.Z. Inst., 12, p. 278, 1880. Phymosoma scolops Selenka and Man, “Die Sipunculiden,” p. 75, 1884. Physcosoma annulatum Benham, Trans. N.Z. Inst., 36, p. 173, 1904.

When I described the Sipunculids of New Zealand (Trans. N.Z. Inst., vols. 36, 37) I had not the opportunity of consulting Selenka's monograph, which was only purchased by the Otago Institute at a later date. I find now that our common Sipunculid, which Hutton described in 1879, is identical with Selenka's P. scolops, a very widely distributed species, which was described five years later. Hutton's brief diagnosis, depending only on externals, is insufficient for identification, and so must give way to Selenka's specific name.

I note that, although Fischer (Die Gephyrea, Abhandl. aus dem Gebiete Naturwiss., 13, p. 10, 1895) regards P. scolops as a variety of the Mediterranean P. granulatum, Shipley still retains it as a distinct species (Willey, Zool. Results Rep. on the Sipunculoidea, p. 106, 1899; and Rep. on the Gephyrea, Pearl Oyster Fishery, Ceylon, p. 174, 1903).

It is evidently very common on the Kermadec Islands, for I have more than fifty I collected on various parts of Sunday Island and on Meyer Island in the ordinary positions—that is, under stones -in rockpools, in amongst coralline algae, &c.

The distribution is very wide.

Aspidosiphon truncatus Keferstein.

Selenka and Man, “Die Sipunculiden,” p. 118, pl. 13, 1884.

Of this identification I do not feel quite certain, for the convolutions of the intestine are fewer, and the longitudinal muscle bands rather more numerous; but as our specimens agree in so many features with those of Keferstein's species, and do not agree with any other description to which I have access, I place it here. The differences are so slight that I do not feel competent to differentiate a new species.

Loc.—Sunday Island, in coralline algae. Six specimens.

Distribution.—Mauritius, Panama, Japan (Ikeda, Journ. Coll. Sci., 20).

Class Chaetognatha.

Sagitta fowleri nom. nov.

Fowler, “On Plankton Chaetognatha of the Bay of Islands, New Zealand,” Ann. Mag. Nat. Hist. (8), 1, p. 240, 1908.

I received seven specimens of a rather large Chaetognath which had been cast ashore, and were somewhat injured, and had unfortunately been placed in a tube rather too small for them, so that they are not only damaged by the sand, but also folded and crumpled. At first I failed to notice the anterior lateral fin, and took it for a species of Krohnia; but the formula given by Dr. G. H. Fowler for an unnamed species from the Bay of Islands