The extension of a trough or basin penetrating the land or an elevation is termed an " embayment " when wide, and a " gully " when long and narrow; and the deepest part of a depression is termed a " deep."
The entire state is included within the Austro-riparian life zone; the higher portions fall within the Carolinian area and the lower portions, including the Gulf and the Mississippi embayment almost to the N.E.
The extension of a basin or trough stretching towards the continent is termed an embayment when relatively wide and a gully when narrow.
The special features of the Gulf Plain are the peninsular extension of the plain in Florida, the belted arrangement of relief and soils in Alabama and in Texas, and the Mississippi embayment or inland extension of the plain half-way up the course of the Mississippi river, with the Mississippi flood plain there included.
In the embayment of the coastal plain some low cuesta-like belts of hills with associated strips of lowlands suggest the features of a beltedcoastal plain; the hillybeltordissected cuesta determined by the Grand Gulf formation in western Mississippi is the most distinct.