I know and apreciate the Atlas of Middle-earth-Revised Edition. It is all trough the work of the autor Karen Wyn Fonstad, but is is base on her study of Tolkiens books. There are many debatable choices he had to make to draw all these maps and pictures. But you can find for nearly all of them sources within the works of JRR Tolkien.
As you can see from the sketch given by Earendilyon, which is in the origin by JRR Tolkien, these islands as you name them (continents would be more fitting) they were intorduced by Tolkien. Your Tolkien dictionary maight be outdated or restricted in its sources.
Respectfully
Findegil
|