(syn. Fregetta Ϯ Black-bellied Storm-petrel F. tropica) Dim. < genus Fregetta Bonaparte, 1855, storm-petrel; "[Key] d1 - Upper surface without pronounced white fringes to the feathers; inner webs of primaries white towards the base: tarsus and toes not scaled, but booted: middle toe and claw longer than each of the others, which are sub-equal: claws oval in shape. . . .Fregolla sub-gen. nov. (F. melanoleuca)" (Mathews 1937, per Laurent Raty).