A' nal, pertaining to the anus, or hinder opening of the intestine.

Anal fin, a ventral median fin of fishes, just back of the anus.

Animal Communities, associations of many animals of the same species.

An ten' na, a segmented sensory appendage on the head of an arthropod.

An ten' nule, a small antenna.

An te' ri or, farther forward, in front of; at the head or forward end.

A or' ta, a large artery arising at the heart and forming the trunk of the arterial system.

Ap' er ture, an opening.

Ap pend' age, a projection from the body, usually one of a pair.

Ar throp' o da, a group of animals with a segmented trunk and paired, segmented appendages.