or Maroni, a river of South America, rises in the Serra Tumucumaque, flows in a northerly direction, forming the boundary between French and Dutch Guiana, and falls into the Atlantic after a course of about 300 miles, in 5° 52' N. Lat., and 53° 50' W. Long. For about 15 miles up it is navigable for small boats; but the number of small islands, rocks, and quicksands that obstruct its course, prevent any vessel of large size from entering; and in the upper part of its course it is so much interrupted with rapids as to be totally unnavigable. It receives on the right the Rio Siburique and the Rio Waki, and on the left the Rio Tapahon.