Ar ti o dac' tyl, an ungulate with an even number of toes.

A sex' u al, without sex.

Au' di to ry, pertaining to hearing.

Barb, one of the lateral outgrowths of the shaft of a feather, forming the vane.

Barb ule, a small outgrowth of the barb of a feather.

Bi lat' er al sym' me try, having the right and left sides mirror images one of the other.

Body cavity, the space between the body wall and the alimentary canal.

Body-wall, the outer wall in bodies of the many-celled animals.

Budding, a form of fission in which a cell or portion of the body forms a small protuberance or bud, which is then cut off from the parent and forms a new individual.

Canals, channels through the body-walls of sponges.