Oulactis cinctum (Sea Anemones of New Zealand)

Oulactis cinctum

Description ¹

Probably just a synonym of Oulactis muscosa (Drayton in Dana, 1846)
Synonyms: Tealidium cinctum Stuckey, 1909 as Metridium muscosum
Habitat
Adherent in cleft of rock, making the animal difficult to remove.

Column
The upper part is brownish in colour, the lower part dirty-white. The upper part is covered with verrucæ in vertical rows; small shells, etc, are attached to these verrucæ. The lower part, which is imbedded in a cleft of the rock, is without the verrucæ, and is channelled by fine furrows. The verrucæ act as suckers, by which the animal covers itself with bits of shell and other débris. In full expansion the column bulges outwards, forming a circular swelling just under the bases of the tentacles. Height, 40 mm, diameter, 30mm.

Oral disc
The colour is pale brown, with a ring of green round the mouth, and a broken ring of yellow round the green.

Tentacles
48 mauve-pink tentacles in four cycles about 16mm long. There are white transverse markings on the inner sides.

Distribution
Island Bay.

Art. XXXVI. - A Review of the New Zealand Actiniaria known to Science, together with a Description of Twelve New Species.
By F.G.A.Stuckey, M.A., Wellington.
Transactions and Proceedings of the Royal Society of New Zealand 1868-1961, Volume 41, 1908, p389

Genus Tealidium (Hertwig).

Paractidœ having the tentacles placed in several rows of uniform size in the same row, and having the body-wall covered with fine papillæ. All mesenteries perfect and gonophoric except the directives. (Hertwig's definition modified.)

This genus was erected by Hertwig for the reception of a form found in the “Challenger” material, a form which agreed with Paractis except in the warty character of the body-wall. In Hertwig's species (Tealidium cingulatum) the wall bulges outwards, forming a girdle below the tentacles. This he attributes to the great development of the sphincter. In the species described below the same thing is seen, though I have no direct evidence that it arises from the cause ascribed by Hertwig. Probably this feature may come to be regarded as of generic value.

Tealidium cinctum (sp. nov.).

Pedal-disc.—Adherent in cleft of rock, making the animal difficult to remove. The mesoglœa is fibrous, and contains numerous lacunæ.

Column.—The upper part is brownish in colour, the lower part dirty-white. The upper part is covered with verrucæ in vertical rows; small shells, &c., are attached to these verrucæ. The lower part, which is imbedded in a cleft of the rock, is without the verrucæ, and is channelled by fine furrows. The verrucæ act as suckers, by which the animal covers itself with bits of shell and other débris. In full expansion the column bulges outwards, forming a circular swelling just under the bases of the tentacles. The ectoderm is somewhat irregular, and there appear here and there spaces between the cells. The nerve-layer is feebly developed. The mesoglœa is well developed, and contains small lacunæ. It runs into the ectoderm in the form of conical papillæ.

Tentacles.—These are 48 in number, apparently in four cycles. Length, about 16 mm. They are pellucid, with a mauve-pink shade. There are white transverse markings on the inner sides. The ectoderm is of the same irregular character as that of the column, but the intercellular spaces are smaller. The nervous layer is well developed, being several cells deep. There is a fair development of the ectodermal muscles, but the endodermal musculature is weak. The lumen of each tentacle is filled with what appears to be hypertrophied endoderm.

Oral Disc.—The colour is pale brown, with a ring of green round the mouth, and a broken ring of yellow round the green. The histological features resemble those of the tentacles.

Sphincter Muscle.—This is mesoglœal and diffuse, extending through the whole wall of the column. There is, however, a decided thickening under the edge of the disc, and this probably constitutes the true sphincter. Hertwig describes a similar sphincter in Antholoba reticulata.

Mesenteries.—There are 24 pairs, 2 pairs being directives. All reach the stomodæum, and are about equal in development. All are gonophoric except the directives. I have made this a generic feature, since Tealidium cingulatum (Hertwig), the only other known species, has all its mesenteries perfect and gonophoric (? directives). The musculature is well developed. (Plate XXIV, fig. 2.)

Gonads.—Placed much as in Paractis ferax, and form large masses between the mesenteries.

Dimensions.—Height, 40 mm.; diameter, 30 mm.

Distribution.—Of the genus—Antarctic Ocean (Delage and Herouard); also New Zealand. Of the species—Island Bay.