DIDUS, or nono, in ornithology, a genus belonging to the order of galline. The bill is contracted in the middle by two transverse rugæ; each mandible is inflected at the point; and the face is bare behind the eyes. The body is blackish and cloudy; the tail is very short, and the upper part of the bill red. It is a native of India; and is incapable of flying, because the wings are not furnished with feathers sufficient for that purpose.
DIDYMUS of Alexandria, an ecclesiastical writer of the fourth century; who, though he is said to have lost his eyes at five years of age, when he had scarcely learned to read, yet applied so earnestly to study, that he attained all the philosophic arts in a high degree, and was thought worthy to fill the chair in the famous divinity-school at Alexandria. He was the author of a great number of works: but all we have now remaining, are a Latin translation of his book upon the Holy Spirit, in the works of St Jerome who was the trans-
lator; short strictures on the Canonical epistles; and Didynamia a book against the Manichees.