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[Latin] Posterior opening of alimentary canal.

The circular opening situate at the inferior extremity of the rectum, by which the excrement is expelled. The fundament. The body. The seat, (F.) Siege, Fondement. Anus also signifies the anterior orifice of the Aqueduct of Sylvius. By some, this Anus, called, also, Foramen commune posterius, has been supposed to form a communication between the back part of the third ventricle and the lateral ventricles. It is closed up, however, by the tela choroidea, and also by the fornix, which is intimately connected with this. The foramen is situate between the commissura mollis of the optic thalami and the pineal gland.

Distal end and outlet of rectum.

The terminal or distal orifice of the alimentary canal.