150 



OEDEE AND SUCCESSION OF EOCKS. 



But if the headland trends off at the pointy, (fig. 85) to 

 the northward, affording a view of the cliffs westward, such 

 view will prove that the appearance from the south is 

 deceptive, for the lines on the western side show a con- 

 siderable angle to the north, and by gradual increase of that 

 angle become vertical at a. 



FIG. 85. 



OEDEE AND SUCCESSION or EOCKS. "We have stated that 

 the fossiliferous rocks follow an invariable order of suc- 

 cession. That this arrangement, although never reversed, 

 is occasionally imperfect ; so that, though we never meet 

 with b going before a, or c preceding 5, yet we occasionally 

 miss not only a single letter, but a succession of letters, 

 and find, in certain localities, that entire groups of strata 

 are wanting, which occur in other places of like geological 

 character. This effect, we observed, may have resulted 

 either from the missing beds never having been deposited in 

 this spot, or from their having been denuded, and carried 

 away by the abrading power of water, before the newer strata 

 were deposited. 



FIG. 86. 



Similar causes may have occasipned either the partial depo- 



