HEYLYN (Peter).
Cosmography in four books. Containing the Chorography and History of the whole World: and all the principal Kingdoms, Provinces, Seas, and the Isles thereof. ...
The five maps are generally (but probably incorrectly) attributed to Robert Morden (d. 1703), based on an early advertisement announcing this edition.
The map of America gives an interesting delineation of the western part of North America, with the Mississippi flowing into the Gulf of Mexico through Texas, California depicted as an island, a legendary inland sea, ‘The Great Lake of Thongo or Thoya’, and a long curved imaginary coastline north from California.
References: ESTC T107951; Worms & Baynton-Williams, on Morden.