25 
upper and lower Keuper are the Labyrinthodont reptiles, 
of singular uncouth form and structure, most nearly 
allied to the recent aquatic salamanders. In the upper 
Keuper the only evidence afforded of their existence are 
the impressions of their footsteps, as they crawled over 
the mud of the Triassic sea, and probably belong to the 
genera Labyrinthodon, Rhynchosaurus, and Cheirotherium. 
These footprints indicate Batrachiaus of small size, with 
the exception of the larger ones of the last-named animal, . 
very imperfect remains of plants are found both in the 
upper and lower Keuper, the only evidence we have of the 
existence of land at this period in England; unless, as 
Professor Huxley now thinks, some of these Labyrintho- 
dants were Dinosaurians, and, if so, terrestrial. It is 
supposed that the sea in which the New Red Sandstone 
was deposited formed a vast inland lake, like the Caspian 
or Dead Sea, still, the absence of shells and the scarcity 
of fish, and, indeed, of fossils generally, is not so easily 
accounted for. My friend, Professor full, and other lead- 
ing geologists incline to the opinion that the New Red 
Sandstone was for the most part deposited in an inland 
sea like the Dead Sea, and the great Salt Lake of America, 
which would account for the prevalence and abundance of 
salt, and the absence of marine shells and other organisms. 
But though this may hold good as far as regards the Red 
Marls, and account for the absence of any fossils in them, 
yet it must be remembered that the upper and lower 
Keuper Sandstone, the former of which is intercalated 
in the Marls, contain fish and reptiles, some of the latter 
terrestrial as well as amphibious, besides plants, so that 
a change in the condition must have taken place during 
the deposition of these sandstones, and in them we may 
look for and, if more frequently quarried, should probably 
find a much larger evidence of the animals and plants 
