a1. Smaller; wing less than 150 mm. Procellariidæ (p. 84) a2. Larger; wing more than 300 mm. Puffinidæ (p. 84)
a1. Smaller; wing less than 150 mm. Procellariidæ (p. 84)
a2. Larger; wing more than 300 mm. Puffinidæ (p. 84)
