38 cm. Medium-sized, long-winged, brownish-grey and white gadfly petrel. Brownish-black cap extending to eye, but interrupted by pale eyebrow. Brownish nape extending towards upper breast to form partial collar. Brownish-grey mantle, upperwing and tail. Pale uppertail-coverts may form narrow whitish band. Entirely white underparts. White underwing with narrow black trailing edge, black tip, extending narrowly onto leading edge. Black bill. Pink legs, pink feet proximally, black distally.