clymenia

from The Century Dictionary.

• noun A genus of fossil tetrabranchiate or tentacu-liferous cephalopods, of the family Nautilidæ, or made typical of the Clymeniidæ, having an internal siphuncle and a discoidal shell with simple or slightly lobed septa. There are many species, ranging from the Silurian to the Chalk.
• noun A genus of porpoises, of the family Delphinidæ.