| diagnosa |
Colonies monosiphonic, consisting either of a mass up to 5 cm in diameter, composed of interwoven stems and branches, or of small stems arising from the substratum. Mass-shaped colonies without a distinct stem. Branches continuously re-branching, usually irregularly in several planes, though sometimes with alternate arrangement. Branches frequently becoming anastomosing tendrils distally. Hydrothecae of lower-order branches in same plane as those of higher order. Stem and branches divided into internodes; one hydrotheca per internode. Hydrothecae alternately arranged in one or in two planes making an obtuse angle. Hydrotheca small, strongly abcaudally directed and adnate to internode for approximately half of its length, though hydrothecae with the free portion longer or shorter than adnate part may be observed. Hydrotheca with a distinct inflexion point where adcauline wall becomes free. Abcauline wall concave, usually with a slight swelling basally. Free part of adcauline hydrothecal wall straight or slightly convex; adnate part almost straight. Hydrothecal aperture
with three blunt cusps separated by shallow embayments. Rim of hydrothecal aperture with frequent renovations. Gonothecae fusiform, arising at hydrothecal base. Gonothecal walls
smooth or slightly wavy, with a short terminal neck, widening distally to the aperture. |