On Acrossota liposclera, a New Genus and Species of Alcyonarian with. Simple Tentacles

Abstract

ABSTRACT The Alcyonarian Colony to be described in the following pages was collected by Prof. A. Willey in the d’Entrecasteaux group of islands, British New Guinea, and sent to me, I am ashamed to say how many years ago, along with a collection of Actiniae and Zoantheae. Partly because of the difficulty and uncertainty of identifying spirit preserved actinians, partly because I had turned my attention to another group of animals, I have neglected this collection until, a short time ago, I began to prepare such specimens as were suitable for cutting into sections with a view of identifying and describing them. Among the Zoanthem I found a colony of small translucent polyps apparently growing in a bunch attached to the fronds of a species of Halimeda. Some of these polyps were partly expanded and exhibited a few simple digitiform tentacles, and this character, together with their general appearance, suggested that they were non-incrusted Zoanthids. On closer examination I found that the polyps arose at intervals from a long, sparsely branched adherent stolon, and that the apparently single colony consisted of several such stolons so closely intertwined that the polyps arising from them were closely bunched together, giving the deceptive appearance of a compact encrusting colony. And, as I shall describe in detail, I found that the tentacles, though simple fingershaped structures, are always eight in number, and that the structure of the polyps, in almost all other respects, presents the well-known characteristic Alcyonarian features.