定義： External ear (pinna) length is a standard measurement in mammalogy, usually measured in a living mammal or a fresh mammal carcass. External ear length is measured from the base of the notch at the bottom of the ear to the apex (highest point) of the ear.
定義： 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.
