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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.

Family Nephthyidæ

Family Nephthyidæ.

Sub-Family Spongodinæ.
Spongodes pallida, sp. nov.
(Plate xii., figs. 7a-c.)

The colony arises from an encrusting base 15 mm. long, 8 mm. wide, and from 1 to 2 mm. thick.

page 222

There are three stems about equal in height and in distance apart; they are 10mm. high, 3 to 5mm. in diameter at their bases, and from 6 to 9 mm. at their summits.

The polyps commence at the bases of the stems, where they are arranged singly, irregularly, and at a considerable distance apart.

On the upper portions of the stems the polyps are in clusters of from three to twelve, and arise from very short secondary branches; on the central stem there are about thirteen such clusters, the largest of which is 3 mm. high and 5 mm. wide.

The polyp heads together with the stalks are from 1 to 1.5 mm. high, and from ·07 to 1 mm. in diameter.

The solitary polyps are given off from the stem at right angles, whilst the clusters on the branches are radiate, and the apertures of many of the lower ones are directed towards the base of the stem.

The stem spicules are arranged transversely, and consist of slightly curved spindles with obtuse ends, having their surfaces closely beset with low rounded tubercles, which are generally smooth, but in some of the larger forms they are minutely denticulate.

Size—·.5 by ·.09, 1·.5 by ·.2 mm.

The spicules of the branches are shorter, stouter, and a little more curved than those of the stem.

The polyp heads have at their bases a number of transversely arranged spiny spindles with acute points. Size—·.4 by ·.03 mm., ·.75 by ·.09 mm. From these there arise larger and longitudinally disposed spicules in pairs, each pair converging at their apices and separated at their bases. Usually one of each pair is longer and projects beyond the margin of the calyx.

These spicules are curved at the base, pointed at their free end, and covered with sharp spines. Size—·.6 by ·.03, ·.8 by ·.05 mm.

The tentacular spicules are distantly spinose, and are arranged en chevron. Size—·.12 by ·.02 mm.

The colour of the colony is uniform creamy-white. Obtained by the tangles at a depth of from 40 to 70 fathoms outside the reef.

Keg. No. G. 1543.

Spongodes curvicornis, Wright & Studer.

Spongodes curvicornis, Wright & Studer, Chall. Rep., Zool., xxxi., p. 220, pl. xxxvi., D., figs. 2, a, b.

One specimen dredged in about 20 fathoms in the lagoon.

The lower branches are connected and foliate or rosette-like as in the type specimen.

page 223

The spindle-shaped spicules on the stem and branches are large, numerous, and easily visible to the unassisted eye; those on the main stem are arranged more or less transversely, varying greatly in size, and are much more strongly spinose than the longitudinally disposed spicules of the branches.

The colour is yellowish-white, the branches and polyps are dark reddish-purple. The larger spicules often attain to a length of 6 mm.

Sub-Family Siphonogorginæ.
Siphonogorgia Godeffroyi, Kolliker.

Siphonogorgia godeffroyi, Kolliker, Wright & Studer, Chall. Rep., Zool., xxxi., p. 236, pl. xxxviii., fig. 4.

There are two small broken specimens which I refer to this species, the larger of which is 25 mm. high and 5 mm. in diameter; the apex is wanting, the remaining portion consists of an erect stem giving off' eight very short branches with terminal polyps. The stem is pinkish at the base, the upper part white, and the polyps very dark red. The longitudinally arranged spicules are large, and consist of straight or curved tuberculated spindles. Size—.3. by ·.3 mm.

Obtained at a depth of from 40 to 70 fathoms.

Siphonogorgia Pallida, Studer.

Siphonogorgia pallida, Studer, Chall. Rep., Zool., xxxii., p. 8, pl. ii., fig. 2 a, b.

One example preserved in formol, in a much broken condition, the actual base is wanting and the upper terminal twigs are reduced to fragments.

The colony notwithstanding its damaged condition is 130 mm. high and 70 mm. wide, the main stem is laterally compressed, its widest basal diameter is 8 mm. and its narrowest 5 mm.

At a short distance from the base a large secondary branch arises, which is slightly less robust than the primary, the general appearance is like the figure on pl. ii. of the Chall. Rep., but the main and secondary branches are more undulate.

The polyps on the lower parts of the colony are in many instances quite flush with the surface, very few projecting like those on the slender twigs.

The colour is bright brick-red with yellow polyps.

page 224

In the walls of the canals there are numerous small spiny-spindles, of a dark carmine colour, offering a striking contrast to the larger spicules which are yellowish-red by transmitted light. Size—·.15 by ·.01, ·.35 by ·.03mm.

Siphonogorgia kollikeri, Wright & Studer.

Siphonogorgia kollikeri, Wright & Studer, Chall. Rep., Zool., xxxi., p. 236, pl. xxiv., fig. 2; Studer, Chall. Rep., xxxii, p. 7, pl. i., fig. 2; pl. v., fig. 3; pl. vi., figs. 4-5.

One specimen with a slightly enlarged base, and measuring 100 mm. in height, but no doubt much higher when perfect; all the terminal twigs are broken.

The colony closely resembles the figure given by Studer, the large cone-shaped polyps being very characteristic.

The colour in spirits is coral-red.

Obtained at a depth of from 40 to 80 fathoms.

Siphonogorgia macrospina, sp. nov.
(Plate xii., figs. 8a-d.)

There are about twenty fragments of what appears to have been one colony. Judging by these fragments the growth was erect and in one plane, lateral branches being given off alternately at intervals of from 5 to 10 mm., but rarely at right angles; the largest branch measures 25 mm. in height, and gives off two alternate branchlets about 10 mm. apart. The thicker branches are a little compressed and 2 mm. in diameter, the slender ter-minal twigs are 1 mm. or less. The branches are rigid but exceedingly brittle owing to the large spicules and the paucity of the cœnenchyma.

The polyps occur at intervals of 3 mm. apart, and are arranged subspirally around the twigs either singly or in pairs, they are placed obliquely to their support, and provided with a slightly projecting calyx; there is a distinct operculum composed of grouped spicules arranged like a ^, and a collar of transversely disposed spicules below the tentacles.

The longitudinally arranged cortical spicules consist of much curved or bent spindles, they are greatly elongated with slender acute points, and the surfaces closely studded with warty tubercles.

The walls of the nutrient canals are thickly charged with long, thin, spiny rods and spindles.

The spicules are as follows:—

(1.)Large elongate curved spindles, densely covered with warty tubercles and tapering to sharp points. Size—1 ·.4 by 15mm., 2. by 21, 3. by 32, 4. by ·.35, 5·.5 by ·.4, 6. by ·.45 mm.page 225
(2.)Long subcylindrical spiny rods and spindles, abundant in the canal walls. Size—·.6 by ·.02, 1·.3 by ·.03, 1·.8 by ·.04 mm.
(3.)Calicular spicules, spiny subfusiforrn, with the free ends acute. Size—·.7 by 12, 1. by ·.15 mm.
(4.)Opercular spicules, distantly spinose. Size—·.3 by ·.03 mm.
(5.)Collar spicules, curved and minutely spinose. Size—·.25 x ·.02 mm.

The colour in spirit is bright yellow, polyps darker.

Obtained outside the reef at a depth of from 40 to 70 fathoms.

Reg. No. G. 1548.