THE NEW RED SANDSTONE SYSTEM. 713 



district of Cheshire, supposes that the sea once flowed up the valley of the Weaver, and 

 was cut off from it by the growth of .a bar, again making its appearance by bursting 

 through the barrier, and again the communication ceasing from the same cause. He 

 conceives, therefore, the two beds of rock-salt to have arisen from the two salt lakes thus 

 successively formed, whose waters were dissipated by the natural process of evaporation, 

 and their salt deposited, the intervening and superior strata of indurated clay proceeding 

 from earthy sediments in the lakes, deposited after the precipitation of the salt. This 

 hypothesis is supported by the phenomena of many salt lakes in the present day, whose 

 waters are lowering through the supply from springs not keeping up with the expendi- 

 ture through evaporation, and whose beds consist of layers of salt, deposited by the over- 

 charged water. There can be little doubt that this is the principle upon which the 

 saliferous deposits have been formed, accelerated in its action by a higher atmospheric 

 temperature, and the frequent play of igneous forces, in earlier ages. But the detail of 

 the theory in the case of the Cheshire salt deposits is open to the objection, that it 

 " employs data drawn from the present relations of land and sea to elucidate the pheno- 

 mena of a period long gone by, and when from unquestionable evidence it is certain that 

 their relations were generally very different." At the same time, it is quite possible, 

 that in the district in question these relations may have been much the same then as at 

 the present. 



It has been observed, that the new red sandstone system, taken as a whole, is remark- 

 ably deficient in the traces of organic life, though, locally, some of its members, as the 

 muschellialk of Germay, are rich in fossils. The remains of about 50 species have been 

 gathered from the formation in England, and upwards of 200 from the same rocks in 

 France and Germany. They consist of marine and a few terrestrial plants, zoophytes 

 and conchifera of several species, fishes belonging to genera which occur in the car- 

 boniferous system, and reptiles. In the hupj'er schiefer, copper-slate of Thuringia, 

 the remains of reptiles have been found saurians, or lizards the earliest instance yet 

 noticed of the occurrence of oviparous quadrupeds in the history of our planet, noticed in 

 the time of Leibnitz, the reptiles being, according to Cuvier, allied to the living Moni- 

 tors. In the year 1834, two species of reptiles were discovered on Durdham-down, 

 near Bristol, in strata belonging to the magnesian limestone the Palasosaurus and The- 



codontosaurus. Relics of a very sin- 

 gular reptile of the lizard tribe were 

 found by Dr. Ward in quarries of the 

 new red sandstone at Grinsill near 

 Shrewsbury the Rhynchosaurus 

 with foot-prints upon the layers of 



Labj rinthodon pachygnatus. stone in the quarries, supposed to have 



been impressed by the animal while walking over the surface of the strata, when in a soft 

 state. Parts of the skeletons of Batrachian reptiles, the Greek name for the frog, 

 but of a gigantic size, have been taken from the sandstones of Guy's Cliff, near Warwick 

 and Leamington, of which the cut exhibits a restoration of one species by Professor Owen. 

 The generic name, Labyrinthodon, refers to the labyrinthine inflections of the teeth. In 

 the upper part of the system on the Continent, the remains of reptiles multiply; and 

 here, in the muschdkalk, occur the bones of some large animals of that class the Pro- 

 tosaurus and Phytosaurus. But the most striking peculiarity of the system is the repeated 

 occurrence of fossil footsteps, tracks of animals on the sandstone, which afford evidence of 

 the existence, at the era of its deposition, of birds belonging to the tribe of Waders, the 

 first indications we have of that highly organised class of vertebrated animals, as tenants 

 of the globe. Ichnites, traces or foot-prints, are peculiar to the new red sandstone system* 



