GEOQOGY UBRARY (_!;gzv:g>Northwestern University Jl lady has been facilitated by a grant from the Graduate School Of NOi`[l1\‘J€SlZ€I'H U’I1lV€I°SllIy to d€fl‘3.y GXPBIISGS lHCLl1'I‘€d il'1 PI‘Cp21l'1l’1g C€l'iZ8.iIl of the illustrations. . _g)RV _ 4;* eeg- °e 5 E o {2 E Li Féwrm g ·‘ .» @$2.2% ” W UNIVERSITY, ALABAMA · OCTOBER 15, 1951 § I § { - Qi .