Definition: the air-filled cavity within the skull of vertebrates that lies between the outer ear and the inner ear. It is linked to the pharynx (and therefore to outside air) via the Eustachian tube and in mammals contains the three ear ossicles, which transmit auditory vibrations from the outer ear (via the tympanum) to the inner ear
Definition: (Quadrupedal jumping) Progression composed of a series of leaps in which the hind legs supply the chief propulsive force, lifting the body completely from the ground and forward. The fore feet touch the ground simultaneously or in close sequence; the body rolls forward over these as in a vault; the hind feet, overstepping the fore feet, at least in greatest speed, come down next and again lift the body forward
Definition: Because of the difference in refractive index between air and water (or corneal tissue), a curved cornea is an image-forming lens in its own right. Its focal length is determined by the radius of curvature of the cornea. Many corneal eyes (eg: in land vertebrates) also have lenses, but the lens is flattened and weakened compared with an aquatic lens; most of the refractive power is provided by the cornea. Corneal eyes cannot focus in aquatic habitat.