PRATUS ISLES, a cluster of islands, shoals, and large rocks, in the Chinese sea, about 300 miles S.S.E. of Canton. The principal island, called Prata, is surrounded by a very extensive shoal of uncertain extent. They are six leagues in extent from north to south, and stretch three or four leagues to the east. Long. 116. 45. E. Lat. 23. 50. N.