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Show 128 PROOFS OF FORMER and would often surround the newer strata on several sides, like the boundary heights of lake basins""'. As might have been expected, the zoophytic, and shelly limestones of the same era, (as the mountain limestone,) sometimes alternate with the rocks of mechanical origin, but appear to have been, in ordinary cases, diffused far and wide over the bottom of the sea, remote from any islands, and where no grains of sand were transported by currents. The associated volcanic rocks, resemble the products of submarine eruptions, the tuffs being sometimes interstrati£ed with calcareous shelly beds, or with sandstones, just as might be expected if the sand and ejected matter of which they are probably composed had been intermixed with the waters of the sea, and bad then subsided like other sediment. 'l'he lavas also often extend in spreading sheets, and must have been poured out on a surface rendered horizontal by sedimentary depositions. 'l'hcre is, moreover, a compactness and general absence of porosity in these igneous rocks which distinguishes them from most of those which are produced on the sides of Etna or Vesuvius, and other land-volcanos. The modern submarine lavas of Sicily, which alternate with beds of shells specifically identical with those now living in the Mediterranean, have almost all their cavities £1led with calcareous and other ingredients, and have been converted into amygdaloids, and this same change we must suppose such parts of the Etnean lava currents as enter the sea to be undergoing at present, because we know the water on the adjoining coast to be copiously charged with carbonate of lime in solution. It is, therefore, one among many reasons for inferring the submarine origin of our ancient trap rocks, that there are scarcely any instances, in which the cellular hollows, left by bubbles of elastic fluid, have not subsequently been :filled by calcareous, siliceous, or other mineral ingredients, such as now abound in the hot springs of volcanic countries. If, on the other hand, we exam\ne the fossil remains in these strata, we £nd the vegetation of the coal strata declared by botanists to possess the characters of an insular, not a continental flora, and we may suppose the carbonaceous matter to • Sec somo ingenious remarks to this effect, in the wo1·k of M. Ad. Bronguinrt, Consid. Gen~rales sur la Nat. de 1a Veg~t. &c. Ann. des Sci. Nnt., Nov. 1828. CHANGES IN PH r "\:SICAL GEOGRAPHY. 129 have been derived part! fro torrents into the sea yd m trees swept from the rock oy O~l ten d'l Scolours and b'l aacnl· par1t ly •f ro 1 Ill sue 1 peaty matter as 1 • \Cns t le rills fl ' } grounus m our tcmperat 1' owmg t lfough marshy b bl 1 e c lmate whe. th . a Y ess rank, and its cle '. . Ie e vegetatiOn is pro- mo.i st an d hot climate of ·t1l composition 1e ss rapi' d than in tlie I.s on 1Y one m. stance yet le. era du nder consi' d m·at.t on. There am.m a I h avm. g been founo nI l .e cor of th e remam. s of a saurian sen.. e s ;;., · The larger c Ill a member f th . 0 · 0 e carbomferous f . VIparous reptil ll . o considerable size in •var 1 . .1 es usua y mhabit rivers I . • m at1tuues d 1 d ot 1er ammals of that c1 a ss l >een , s' anb dI a crocodiles and secondary formations h a a un ant as in some . ' we must ave i D . d I . many rivers, which could on! ha d ? ene t le existence of Nor have the bones of an ty ve. ramed large tracts of land I· nvesti·g ati.O ns. Had Y fe rrIe stnal m amma1 J· a rewarded our• f] any o t 1ese bel · o ~rge size, occurred, they would ha ongm~ to quadrupeds agamst the resemblance of th . ve supplied an argument ~o !hose of the modern Paci~c an~tent. northern archipelagos Indigenous quadrupeds 11 b' smce ll1 the latter no great l ave een met . 1 . a genera character of small . ] d Wit 1. It Is, indeed tance from continents to b Ils an s situated at a remote dis' . 1 ' e a togethe d t' ~ lupe( s, except such as app t 1 r es Itute of land quad b ' ear o lave b - ,Y man. Kerguelen's land I . h . een conveyed to them ~Ize, placed in a latitude cor~e; uc . Is of no inconsiderable Islands, may be cited pondmg to that of the Sci'll ~ . 1 . as an example y el'tt e Islands in the p 'fi ' as may all the groups of aCI c ocean b t h no quadrupeds have been fou e ween t e tropics, where the. rat, which have probab1 ndbe::cep~ the dog, the hog, and natives, and also bat 1 . h y brought to them by tl th e c1la m. of islands ~' 1w . uIc may h ave macl e thei. r way alo 1e G · w uc 1 extend f I ng z umea far into th 1 . rom t le shores of N 1 e sou t 1ern Pacifi t ew ea and, which may be c . Even the isles of New compared to Ireland an d S cotland "' Amongst oth r, · berland th or osslls collected from th . ' o Rev. Charles V. V crnon h b . e mountam-limostonc of N ortht1 , U . as eeu fortunate onou 1 m ~aving found a saurian ~~~s ~ese dominum fecisse 1acertoo g l lmprt>ssion of fi e c ra together with t •ll ' stone. In th: sorn ana~og?us to thoso of the c!~-~ ro m~d ~china1 spines, and an occurs in tho lo nme district, coal of a good ~-~stu es m the moWltain limePhil. Soc. for 1;~~ IJnrt of the limestone series. ~: I y 1 ~d in great abundance t p . 1 'P• 14. nua eport of the Yorkshira nc lard's Ph si al . " Vor .. I. y c History of Man, vol. i., p. 75. K |