Geology of England mid Wales, &c." 233 



transition) corals, encrinites, and testacea, different how- 

 ever from those now known, appear at first sparingly ; the 

 fossil remains of the carboniferous limestone are nearly of 

 the same nature with those in the transition rocks, but 

 more abundant ; the coal measures, however, themselves, 

 which repose on this limestone, scarcely present a single 

 shell or coral ; but on the contrary abound with vegetable 

 remains, ferns, flags, reeds of unknown species, and large 

 trunks of succulent plants, strangers to the present globe. 

 Upon the coal rest beds again containing marine remains 

 (the magnesian limestone) ; then a long interval (of new 

 red sandstone) intervenes, destitute almost, if not entirely, 

 of organic remains, preparing as it were the way for a new 

 order of things. This order commences in the lias, and is 

 continued in the Oolites, green, and iron sands, and chalk. 

 All these beds contain corals, encrinites, echinites, Crusta- 

 cea, testacea, vertebral fishes, and marine oviparous quad- 

 rupeds, yet widely distinguished from the families contained 

 in the lower beds of the transition and carboniferous class, 

 and partially distinguished among themselves according to 

 the bed which they occupy. Hitherto the remains are al- 

 ways petrified (i.e. impregnated with the mineral substance 

 in which they are imbedded ;) but lastly, in the strata 

 which cover the chalk we find the shells merely preserved, 

 and in such a state, that when the clay or sand in which 

 they lie is washed off, they might appear to be recent, had 

 they not lost their colour and become more brittle. Here 

 we find beds of marine shells alternating with others pecul- 

 iar to fresh water, so that they seem to have been deposit- 

 ed by reciprocating inundations of fresh and salt water. In 

 the highest of the regular strata, the crag, we at length find 

 an identity with the shells at present existing on the same 

 coast ; and lastly, over all these strata, indiscriminately, 

 there is spread a covering of gravel (seemingly formed by 

 {he action of a deluge which has detached and rounded by 

 attrition, fragments of the rocks over which it swept) con- 

 taining the remains ot numerous land quadrupeds, many of 

 them of unknown genera or species (the mastodon and the 

 fossil species of elephant or mammoth, bear, rhinoceros, 

 and elk) mingled with others equally strangers to the cli- 

 mates where they are now found (hyaenas, <Sic.), yet associa- 

 ted with many at present occupying the same countries," 

 n. 11, In trod. 



VoL.VIl.— 'No. 2. .30 



