12 J? M. Eichwald's Geological Remarks upon the 



species, a» casts and indistinct impressions in the limestone. 

 Venus Cratlma is very abundant in the Black Sea ; but, in the 

 Caspian Sea, it is found no longer in the living state, and it 

 is but seldom that on the north and west coasts of the same 

 that we find the decayed remains of the above shell. In 

 other masses of limestone, on the contrary, the number of fossil 

 shells is much more considerable. This limestone, which is of 

 a pale rose-red colour, is not particularly compact, and may ra- 

 ther be called crumbling ; since, from the many shells which ad- 

 here together, empty spaces are found over the whole of it. It 

 evidently forms a calcareous tuff'a, containing shells of the new- 

 est tertiary formation, the calcaire moellon of the French, such 

 as it is found upon most European coasts, as on those of Nor- 

 way, France, Spain and Italy. It is found particularly exten- 

 sive upon the north coast of the Black Sea ; for I have ob- 

 served it from the mouth of the Dnester, as far as the Bug 

 and the Dnieper. The shells it contains, which are in the form 

 of casts, often appear very large, and mostly belong to a species 

 of Venus, But they are not formed like the existing Venus Gal- 

 Una of the sea. Their hinge end is not so pointed, and besides 

 the shell is much broader, at the same time thinner ; hence it is 

 transparent, and so fragile that it is quite destroyed, the cast 

 only remaining. We easily observe upon these casts large im- 

 pressions of the animal, which appear here as considerable projec- 

 tions, and are situated on each side of the hinge. The hinge is 

 in this case nearer the middle, and not, as in Veiius Gallina, 

 very much to one side. Upon the outside of the shell we see on 

 every part likewise cross stripes. 



There is another and extensive mountain mass which rests 

 upon the limestone, which does not contain shells: it consists en- 

 tirely of casts of fossil shells, which are all of a medium size, ad- 

 here close to one another, and form nearly the whole of this for- 

 mation, without any intervening mass to bind them together. 



It is but seldom that we see thin white shells, which from 

 their shape resemble the Venus, and also exhibit cross lines. To 

 judge from the position of the hinge, this appears to be the same 

 as the preceding, only smaller. The rock itself is white, and its 

 hardness is greater than that of the rock above named. So far 

 as I traced along the coast, and observed the rugged towering 



