Figure 1: Schematic diagrams showing external (a) internal (b), and (c) morphology of the oral region and associated structures in a bowhead whale, Balaena mysticetus. At lower left (b) is a frontal section (anterior at top) and at lower right (c) a transverse section (dorsal at top), each at the level of the dashed horizontal line intersecting the other diagram. Prey-laden water enters the mouth anteriorly through a subrostral cleft (between baleen racks) and flows through and around the baleen plates and fringes, exiting, after prey have been removed, behind the lips.