E. W. Hilgard on the Quaternary of Mississippi. 321 
to be parallel, not only geographically, but geologically and ge- 
netically, to the en A va ahs level belt of land timbered 
prevalently with Post Oak, and popularly known as “the Flat- 
woods” ($561, ff.). North of Ocktibbeha county, Miss., they 
are separated from the prairie belt by intervening ridges, but 
farther south the two trails coalesce, the difference of soil alone 
marking, in some degree, their confines. That difference is mani- 
festly owing to, and parallel with, that between the subjacent 
Am. Jour, Sc1.—Seconp Sentzs, Vou. XLI, No. 123.—May, 1866, 
41 
