DISTAFF THISTLE.** See Botany Index.

**ATRÆTI,** in Medicine, infants having no perforation in the anus, or persons imperforated in the vagina or urethra.

**ATRAGENE.** See Botany Index.

**ATRAPHAAXIS.** See Botany Index.

**ATREBATII,** a people of Britain, seated next to the Bibroci, in part of Berkshire and part of Oxfordshire. This was one of those Belgic colonies which had come out of Gaul into Britain, and there retained their ancient name. For the Atrebati were a tribe of the Belgæ, who inhabited the country which is now called Artois. They are mentioned by Caesar among the nations which composed the Belgic confederacy against him: and the quota of troops which they engaged to furnish on that occasion was 15,000. Comius of Arras was a king or chieftain among the Atrebati in Gaul in Caesar's time: and he seems to have have possessed some authority, or at least some influence, over our Atrebati in Britain; for he was sent by Caesar to persuade them to submission. This circumstance makes it probable that this colony of the Atrebati had not been settled in Britain very long before that time. The Atrebati were among those British tribes which submitted to Caesar; nor do we hear of any remarkable resistance they made against the Romans at their next invasion under Claudius. It is indeed probable, that before the time of this second invasion they had been subdued by some of the neighbouring states, perhaps by the powerful nation of the Cattivellani, which may be the reason they are so little mentioned in history. Calleva Atrebatum, mentioned in the seventh, twelfth, thirteenth, and fourteenth Itineraries of Antoninus, and called by Ptolemy Calceu, seems to have been the capital of the Atrebati; though our antiquaries differ in their sentiments about the situation of this ancient city, some of them placing it at Wallingford, and others at Ilchester.