A SUMMER RAMBLE AMOXG THE HEBRIDES. 55 



resembles in type a recent one than any I have yet seen in 

 a secondary deposit, except perhaps in the Weald of Moray, 

 where we find in one of the layers a Planorbis scarce distin- 

 guishable from those of our ponds and ditches, mingled with 

 a Paludina that seems as nearly modelled after the existing 

 form. From the absence of the more characteristic shells of 

 the Oolite, I am inclined to deem the deposit one of estuary 

 origin. Its clays were probably thrown down, like the silts 

 of so many of our rivers, in some shallow bay, where the 

 waters of a descending stream mingled with those of the sea, 

 and where, though shells nearly akin to our existing peri- 

 winkles and whelks congregated thickly, the Belemnite, scared 

 by the brackish water, never plied its semi-cartilaginous fins, 

 or the Nautilus or Ammonite hoisted its membranaceous sail 

 We pass on towards the north. A thick bed of an ex- 

 tremely soft white sandstone presents here, for nearly half a 

 mile together, its front to the waves, and exhibits, under the 

 incessant wear of the surf, many singularly grotesque combi- 

 nations of form. The low precipices, undermined at the base, 

 beetle over like the sides of stranded vessels. One of the pro- 

 jecting promontories we find hollowed through and through 

 by a tall rugged archway ; while the outer pier of the arch, 

 if pier we may term it, worn to a skeleton, and jutting 

 outwards with a knee-like angle, presents the appearance of 

 a thin ungainly leg and splay foot, advanced, as if in awk- 

 ward courtesy, to the breakers. But in a winter or two, 

 judging from its present degree of attenuation, and the yield- 

 ing nature of its material, which resembles a damaged mass 

 of arrowroot consolidated by lying in the leaky hold of a 

 vessel, its persevering courtesies will be over, and pier and 

 archway must lie in shapeless fragments on the beach. 

 Wherever the surf has broken into the upper surface of this 

 sandstone bed, and worn it down to nearly the level of the 

 shore, what seem a number of double ramparts, fronting each 



