Halecium sessile Norman, 1866

Hydrorhiza reptant on substrate, stolons tubular.

Stems monosiphonic, to 4 mm high, straight to slightly zig-zag, simple or sparsely branched near base. Stem internodes widening distally to hydrophore, nodes transverse, deep.

Hydrophore short, primary hydrotheca very shallow, sessile or very closely adpressed to internode at level of node, shallow dish-shaped, sloping gently downwards away from internode, diaphragm distinct with a row of desmocytes above. Margin circular, not everted. Secondary hydrophores rare, on lower parts of stems, issuing from diaphragm of preceding hydrotheca, adcauline wall deeply indented at level of diaphragm. Perisarc smooth throughout, thick on proximal parts of stems, becoming very thin on hydrotheca.

Hydranths robust, very extensible with about 24 stubby tentacles.

Colour yellowish-brown.