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General Description

Diagnosis: The column of preserved contracted specimens is smooth and delicate, with a diameter that is more or less equal along the length of the column. The diameter at the base of the column is between 19 - 35 mm, and the column measures between 15 - 40 mm in height. There is a distal belt of 24 perforate papillae. The column of live specimens is trumpet shaped, and yellowish to white in colour. The tentacles are moderately long and blunty conical without aboral thickenings. The tentacles have spirocysts and basitrichs. Holotrichs only occur in the tips of the tentacles. Holotrichs are also present in the column and pedal disc. The mesenteries are hexamerously arranged, with only the first cycle being perfect.

Oral disc and tentacles: The oral disc is slightly domed, with a broad, tentacle-free space surrounding a prominent mouth. In live specimens the oral disc is light brown and translucent, with faint dark lines marking mesenterial insertions. In preserved specimens the oral disc is a uniform opaque cream colour. The mouth is elevated on conical hypostome, with large lips. The mouth, lips, siphonoglyphs and actinopharynx are all cream to white in colour in live specimens. In preserved specimens they are the same colour as the column and oral disc. There are up to 96 tentacles in four crowded marginal cycles. The tentacles of the inners cycles are longer than those of the outer cycle. In preserved specimens the tentacles are blunt and longitudinally furrowed with a pore at the tip. They have the same colour as the column, and are ca. equal in length to the oral disc radius. In live specimens the tentacles are longer and more sharply tapering, with the tentacles of the inner cycle much longer than the oral disc diameter. Some preserved specimens were missing tentacles. The point of attachment between the margin and tentacle was uniform rather than being ragged, suggesting autotomy rather than damage. The longitudinal musculature of the tentacles is ectodermal.

Base and column: In preserved contracted specimens the column is smooth, stout and cylindrical or top-shaped. The column measures between 15 - 38 mm in height and 13 - 35 mm in diameter at the base. In life specimens the column is trumpet shaped, flaring slightly from the base. The column is thin walled and delicate, with 24 small but prominent mound-like papillae in endocoels between the midline of the column and the region of the marginal sphincter. The papillae are solid, not adhesive or histologically differentiated into verrucae, with central cinclide. The colour of the column in both live and preserved specimens is cream. The mesenterial insertions are visible as distinct opaque white lines. In contracted specimens the mesenterial insertions furrow the column. The column musculature is strong, mesogleal and concentrated into a mesogleal marginal sphincter distally. The sphincter lies closer to the gastrodermis than the epidermis and does not taper. There are no fosse. The mesogleal sphincter forms a marginal ring. The pedal disc is adherent and muscular. It is the same colour as the column. The basilar muscles are poorly developed.

Mesenteries and internal anatomy: The mesenteries are arranged hexamerously in four cycles, with those of the first cycle being perfect. There are two pairs of directives, each attached to a prominent siphonglyph. There are an equal number of mesenteries distally and proximally. The mesenteries of the first three cycles (including directives) are fertile and with filaments. The mesenteries of the fourth cycle are small, weak and lacking in filaments and gametogenic tissue. The longitudinal muscles of the mesenteries are weak. The retractor muscles are diffuse and span most of the distance between the body wall and the filament, with many short, branched processes. The parietobasilar muscles are not distinct from the mesenterial lamella, with few short, broad processes and no pennon.

Cnidom: Robust and gracile spirocysts, basitrichs, holotrichs and microbasic p-mastigophores.

(Zelnio et al., 2009)


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