266 FOSSIL FISHES. 
and numbers, and of the functions they dis- 
charge in the economy of nature, he has left to 
his able successors. 
The fact of the formation of so large a portion 
of the surface of the earth beneath the water, 
would lead us to expect traces of the former 
existence of Fishes, wherever we have the 
remains of aquatic MoUusca, Articulata, and 
Radiata. Although a few remarkable places 
have long been celebrated as the repositories of 
fossil Fishes, even of these there are some, 
whose geological relations have scarcely yet been 
ascertained, while the nature of their Fishes 
remains in still greater obscurity.* 
The task of arranging all this disorder has 
cast in the British Museum, taken from another slab found in 
the same quarries, and impressed with footsteps of some small 
aquatic Reptile. 
Some fragments of bones were found in the same quarries with 
these footsteps, but were destroyed. 
A thin deposit of Green Marl, which lay upon the inferior bed 
of sand, at the time when the footsteps were impressed, causes the 
slabs above and below it to part readily, and exhibit the casts 
that were formed by the upper sand, in the prints that the 
animals had made on the lower stratum, through the marl, while 
soft, and sufficiently tenacious to retain the form of the footsteps. 
* The most celebrated deposits of fossil Fishes in Europe are 
the coal formation ofSaarbriick, in Lorraine; the bituminous slate 
of Mansfeld, in Thuringia; the calcareous lithographic slate of 
Solenhofen ; the compact blue slate of Glaris ; the limestone of 
Monte Bolca, near Verona; the marlstone of Oeningen, in Swit- 
zerland ; and of Aix, in Provence. 
Every attempt that has yet been made at a systematic arrange- 
