Agalmatidae Brandt, 1835

Pugh, P. R. & Baxter, E. J., 2014, A review of the physonect siphonophore genera Halistemma (Family Agalmatidae) and Stephanomia (Family Stephanomiidae), Zootaxa 3897 (1), pp. 1-111 : 18

Family Agalmatidae Brandt, 1835

Diagnosis: Physonect siphonophores whose nectophores, when present, are budded off on the dorsal side of the nectosome. Descending mantle canal present on nectophores, when such are developed. Species are monoecious. For most species, with the possible exception of those of the genus Athorybia , the adult tentilla are involucrate.

Genera: Agalma , Halistemma , Nanomia , Athorybia and Melophysa , the last two being short-stemmed forms with, in the genus Athorybia , the total suppression of the nectosome.

Remarks: The family Agalmidae , based on the genus Agalma Eschscholtz, 1825 , was established by Brandt (1835); the name coming from the Greek for glory or delight. However, Poche (1914) pointed out that, because of the Greek declension of the noun, the name of the family should correctly be written as Agalmatidae , and this form has been generally used after it was adopted by Cairns et al. (1991).

Genus Halistemma Huxley, 1859

Diagnosis: Agalmatid siphonophores with characteristic arrangement of ridges on the nectophores; basically consisting of pairs of upper and lower lateral, lateral, and vertical lateral. Characteristic sinuous arrangement of the lateral radial canals on the nectosac. Adult bracts of at least two different types. In development the colonies pass through a distinctive post-larval Nectalia stage . Tentilla with single terminal filament, often ending in a cupulate process. Involucrum vestigial or covering only first one or two spirals of cnidoband.