High, and has a horny, helmet-like protuberance on the crown of its head; the front of the neck is naked and provided with two brightly-coloured wattles.
Dermatocera, foot with a horn-shaped protuberance at its posterior end.
After the entrance of the pollengrain the pollen-chamber becomes roofed over by a blunt protuberance of nucellar tissue.
The flipper is short, broad, and truncated, and the dorsal fin a mere low protuberance.
They are specially distinguished by the great development of the anterior half of the zygomatic arch of the skull, and by the presence in the boars of a horny protuberance of the skin in front of each eye, which overlies a tuberosity on the nasal bone; the molars are also small and simple, and the anterior premolars are generally shed at an early stage of life.
The second thoracic ring is humped, and there is a spine-like horn or protuberance at the tail.
A study of the figure will show that the centrifugal force round the axis RR will act on the equatorial protuberance of the rotating earth so as to make it tend in the direction of the arrows.