492 FISHES. 



and impressions or casts ; and some remains of crustaceous ani- 

 mals have been found in the same place. Shells are extremely 

 rare. Many genera and species of fishes which occur in this 

 stratum have been described by Dr Volta, brother of the ce- 

 lebrated physician of the same name, in a work published at Ve- 

 rona in 1796, and by Blainville in the twenty-seventh volume 

 of the New Dictionary of Natural History. Fossil remains of 

 fishes have also been found in the Vicentine, at Frioul, in Dal- 

 matia, Cerigo, Malta, Sicily, and Barbary, in strata of a similar 

 kind. 



In what have been called the fresh water formations, fossil 

 remains of fishes have been met with in various parts of the con- 

 tinent of Europe. In the gypseous formations at Aix, and in the 

 neighbourhood of Paris, are species of the genera Mugil, Perca, 

 CyprinuS) Sparus, Poecilia, Salmo, and other fresh water fishes. 

 At the village of CEningen, on the right bank of the Rhine, as 

 it leaves the lake of Constance, in a quarry 500 feet above the 

 level of the lake, and on the southern slope of a mountain, cal- 

 led Schienerberg, many species of fishes have been discovered. 

 The substance in which they are inclosed is a kind of fetid slate 

 or schistus, coloured white or gray, containing a great quantity 

 of clay and fragments of vegetables. The specimens found 

 here, often very complete and even with the scales, are of the 

 genera Petromyxon, Murcena, Cobitis, Salmo, Esoar, Cypri- 

 nus, Clupea, Pleuronectes, Scomber, and Trigla. 



Other remains of fishes occur in various parts of the world, 

 and in very different formations. These, consisting of detach- 

 ed vertebras and teeth, are found in transition rocks, compact 

 limestone, chalk, gypsum, and alluvial strata. Fossil teeth or 

 ichthyodontes occur in great quantity in Malta and Sicily. 

 They are common in Calabria, Tuscany, the teritory of Sienna, 

 the Plaisantine, and probably in all the subapennine hills ; in 

 the neighbourhood of Brussels, in the hill of St Peter near Maes- 

 tricht, the environs of Montpellier, in the neighbourhood of Paris, 

 London, &c. These teeth are often of their natural colour, or 

 tinged with yellow; but sometimes they are coloured bluish black, 

 or ochreous red, according, it is thought, to the nature of the strata 

 in which they are imbedded ; and even some have undergone a 

 change in their chemical composition, as those which have been 

 converted into the gem named the turquoise. Those of a flat- 



