Genus Merga Hartlaub, 1914

Merga Hartlaub, 1914: 249;

type species Pandea violacea Agassiz & Mayer, 1899 by original designation.

Tiarula Hartlaub, 1914: 253; type species Tiara tergestina Neppi & Stiasny, 1912 by original designation.

Mergintha Hartlaub, 1914: 250; type species Mergintha lobianci Hartlaub, 1914 by monotypy.

Janiopsis Bouillon, 1980: 328; type species Janiopsis costata Bouillon, 1980 by monotypy; invalid junior homonym of Janiopsis Rovereto, 1899 [ Gastropoda, Buccinidae].

Diagnosis: Pandeid medusae with smooth or granulate adradial or interradial gonads, with mesenteries, stomach with cross-shaped base, manubrium not twisted, with simple or faintly crenulated oral lips; four, eight, or more tentacles, with or without rudimentary bulbs or tentacle-stumps, with or without ocelli.

Hydroids, where known, colonial, arising from tubular, ramified hydrorhiza, cauli slightly branched or not, with or without pseudohydrotheca, when present not enveloping tentacles, one whorl of filiform tentacles. Medusa buds arise from stems or stolons.