Whet.-Slate. 333 2. This fpecies does not include every kind of tvhetftone which is in ufe, for fome are of clay flate, or compadt limeftone, others are pf fandftone. 3. It is dillinguifhed from all other flaty foffils by its fracture. .oV ' r ' t .1 .4 ,•< J -'nodi ,r .V UYa.» Dfit ■ ' ■'( ''■ ' ' l ' : aq bits ti ? ’ hP'>'y » .i ~f -7! JM> V : • . -'•isif o?nt ?• 5 ; '. . . '-itcq ji x r.' r - ■ y ?d ; .•/ ’• fti!;:7/:/; r l‘o;u: \y.», i y^ > • <'lr» bjisvoo •s.-}"" v:.. ••uiip.iT-e X X TWENTIETH
