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The Atoll of Funafuti, Ellice group : its zoology, botany, ethnology and general structure based on collections made by Charles Hedley of the Australian Museum, Sydney, N.S.W.

[X.] — The Alcyonaria. — Part1

page 213

The Alcyonaria.

The Alcyonaria collected at the Ellice Group by Mr. C. Hedley, prove to be of more than ordinary interest, inasmuch as the Collection now dealt with includes four new species, and many rare or but little known forms.

There are three species of the genus Sarcophytum, one of which was originally described by Dana as Alcyonium latum, from Fiji; herein it is referred to the genus Sarcophytum, to which it undoubtedly belongs.

The genus Lobophytum is represented by six or seven species; two are described as new, and four others have been re-described and illustrated, with a view to aid in their determination in the future.

In dealing with the species described by the earlier authors, there is a considerable amount of doubt as to their specific identity, from the fact that the characters afforded by the spicules have generally been ignored, and only the external features given. In such cases I have thought it better to accept the species, when they agreed fairly well with the descriptions, rather than describe them as new.

Under this category are included Alcyonium tuberculosum, Q. & G., A. confertum, Dana, and A. viride, Q. & G. The latter appears to differ greatly from the other species under notice, and Studer refers it to the genus Lobularia in his account of the Alcyonaria of S.M.S. "Gazelle."*Judging by the spicules alone, the species herein enumerated and referred to the genus Lobophytum are very heterogeneous, displaying great variation in the size and also in the tuberculation of the larger spicules; the tubercles are not in whorls but are irregularly scattered, this is so in L. tuberculosum, L. confertum, and L. densum, which in this respect are closely allied to L. marenzelleri, and also in the size of the siphonozooids, which are minute and almost rudimentary.

page 214

The Nephthyidæ are represented by two species of Spongodes, one—S. pallida—being regarded as new.

Of the genus Siphonogorgia no less than three out of the seven known species are in the Collection, together with a new species possessing very large spicules, the external ones of which resemble those of Spongodes.

I have again to acknowledge my obligation to my colleague, Mr. Edgar R. Waite, for the admirable pen and ink drawings, from which the accompanying illustrations were photographically reproduced.

Mr. Charles Hedley supplies the following field notes:—

"The Alcyonidæ, such as Lobophytum and Sarcophytum, especially flourished on the numerous small reefs which stud the lagoon, where they grew from low water to as deep as the eye could follow. Like the hard corals with which they were interspersed, they loved clear, smooth water, and a rocky bottom, and could not endure sand or mud. So plentiful were they in such spots, that I have often walked for twenty or thirty paces treading upon Alcyonaria continuously. So much do these resemble in a general way some of the hard corals, among which they grow, that I have often stooped to feel whether the object of my attention were hard or soft. On shady days the polyps might be seen fully exserted, but in bright sunshine they were invariably retracted. All the specimens collected were taken at low water by wading on the lagoon reefs opposite the anchorage.

"The Nephthyidæ, embracing Spongodes and Siphonogorgia, could not be reached but by one having steam power at command. The only day a steam launch was placed at my disposal, I spent the time dragging tangles across and along the steep and narrow slope west of the atoll, between forty and seventy fathoms. From this rocky mountain side were procured one species of Spongodes, four species of Siphonogorgia, and a number of Gorgonias." These latter will be dealt with in the next Part.