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ON A NEW SPECIES OF ALLOPORA.

BY THE REV. J. E. TENISON-WOODS, F.G.S., &c.

Sub-King. Coelenterata. Phylum Nematophora. Sub-Ord. Hydro-Corallinoe. Family Stylasteridoe.

Genus Allopora. Generic character. Cyclo-systems, budding from one another somewhat irregularly.

   ALLOPORA INCOMPLETA, spec. nov.

Coral dendroid with irregularly cylindrical branches, loosely straggling, free. Coenenchyma well developed and distinctly

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undulately grooved with longitudinal striae. Grooves narrower than the interstices. Culices somewhat close with an irregular quincuncial arrangement, but on the youngest branches sometimes alternate, projecting, semicircular, the septa of the upper side being replaced by a transverse ridge. Septa six to nine, ordinarily eight, thin at base, rapidly narrowing. All round the calices an irregular series of ampullae as large as the calices.. No columella visible in the somewhat deep fossa. The diameter of the branches is about two millim., diminishing to half that measurement near the tips. At the base there is a thick coenenchyma from the coalescence of the branches, and in this the calices are clustered irregularly, and the calices are complete circles in some few cases, and do not project so much as those on the branches. The diameter of the largest is scarcely half a millimetre.

This species possesses remarkable characters which distinguish it from any other. Such are the semicircular calices, and the ridge which separates the upper, or non-septate side from the coenenchynia. The small number of the septa also distinguishes it, and makes a correction necessary in the definition, which says that there are always 12 tentacles in the gasterozoids.

These specimens were dredged in great numbers from a depth of 30 fathoms off Port Stephens, and the color was a fresh pink. Type specimens in the Sydney Museum.