Pterodroma cooki masafuerae Lönnberg, Nat. Hist. of Juan Fernandez and Easter Island, vol. III, Upsala 1920, p. 14.= Pterodroma longirostris Stejneger, 1893
Holotype ? : Male ad., Masafuera, Juan Fernandez Islands. 1. III. 1917. K. Bäckström leg. No. 337. - Measurements of type : wing : 212 mm.; tail : 104 mm.; culmen : 25 mm.; tarsus : 27 mm.Click on the picture for enlargement.