In the Laysan and Black-footed Albatrosses the inner and outer primaries are replaced in opposite directions, making it clear that they are part of separate molt series. Howell (2006) argues that Langston and Rohwer (1995) were wrong about the location of the division between these molt series. While Langston and Rohwer interpreted this division as lying between primaries 5 and 6 (P5/6), Howell (2006) suggests that this divide lies between P7 and 8. Howell further posits that the mode of feather replacement in the inner primary series is stepwise, meaning that multiple waves of active feather replacement sometimes proceed simultaneously through the inner primaries.