rOSSlL, RELICS OF EXISTING GENERA. 1 23 



carian pines, of bananas, tree-ferns, huge cacti and 

 palms ; that the marshes were filled with rush-like plants 

 15 or 20 feet high, and the eo verts with ferns like the 

 undergrowth of a West India island. 



The chalk system is rich in extinct corals, zoophytes, 

 and echinoderms. Our lofty chalk hills and the white 

 cliffs of Dover have been formed through a long succes- 

 sion of ages at the bottom of a deep sea. From the 

 Secondary we advance to the Tertiary periods. In ge- 

 neral, says a talented writer, " No contrast can be more 

 complete than that between the secondary and the tertiary 

 rocks ; the former retaining so much uniformity of cha- 

 racter, even for enormous distances, as to appear like the 

 effect of one determined sequence of general physical 

 agencies ; the latter exhibiting an almost boundless local 

 variety, and relations to the configuration of land and 

 sea not to be mistaken. The organic bodies of the 

 secondary strata are obviously and completely distinct 

 from those of the modern land and sea ; but in the ter- 

 tiary deposits, it is the resemblance between fossil and 

 recent kinds of corals, shells, plants, quadrupeds, and 

 other vertebrata, which first arrests the judgment. In 

 general there is a decided break between the two groups 

 of rocks, a discontinuity which is nowhere completely 

 filled. Yet besides the pseudo-tertiary or transition 

 chalky rocks of Maestricht and the Pyrenees, and the 

 conchiferous marls of Gosau, we have in England and 

 France above the chalk a prevalence of green and ferru- 

 ginous sands similar to those below. Perhaps they have 

 been derived from the waste of those older rocks, Mr. 

 Lyell supposes the tertiaries of the London basin to have 

 been formed from the waste of the secondary strata of 

 Kent, Surrey, Sussex, and Hampshire. With the ter- 

 tiary system came into existence, if we may trust the 

 evidence which the earlier strata present, many races of 

 quadrupeds, some birds, reptiles, and fishes, extremely 

 analogous to, though for the most part specifically dis- 

 tinct from, the modern denizens of land and water ; 

 thousands of corals, shells, Crustacea, &c., which present 

 with living races quite as great analogy as obtains be 



