Neighbourhood oftJie Caspian Sea. 125 



cliffs, which reach to the height of 480 feet, I found this tertiary 

 shelUimestone to prevail everywhere. It is mostly placed ho- 

 rizontally ; it seldom deviates from this position, and composes 

 the whole of the inlet of the Tjukkaragan. Upon the coast, 

 vast blocks of this limestone, mixed with fragments of another 

 limestone without petrifactions, are observed thrown together in 

 wild confusion, through which it is with the greatest fatigue 

 and difficulty that we can make our way. They appear to have 

 been torn asunder and thrown down by means of some great 

 convulsion. Above, on the contrary, there is a very flat coun- 

 try, formed of the same shell-limestone, which is covered with 

 a very stinted vegetation. 



We may mention lastly, as worthy of notice, a greyish-black 

 and tolerably soft tertiary limestone, which generally forms the 

 upper covering of both the species of shell-limestone already 

 mentioned. It consists throughout of small fossil Serpulay 

 hardly a line thick, of an unknown species *. These sea ani- 

 mals live no longer in the Caspian Sea, but in the Black Sea. 

 I have observed a species of Serpula, very nearly allied to the 

 above, but which, however, is smaller, and there lives upon a 

 fucus. But fossil spiral tubes of Serpulae are found more abun- 

 dantly in Volhynia and Podolia, in tertiary limestone over chalk, 

 of which they form the principal material. Equally remarkable 

 is another A^oZ^w-shaped fossil which is found in the above ser- 

 pulitic limestone : it occurs only in single specimens, with many 

 small siliceous pebbles intermixed, and generally does not exceed 

 nine lines in length. This Solen likewise is entirely awanting 

 in the Caspian Sea ; but I have found it upon the east coast of 

 the Black Sea. This furnishes us with a new proof of' the simi- 

 lar'ity ofthejhrmer animal kingdom of the Caspian Sea with 

 what at present exists in the Black Sea ; whence we iiifer the 

 early union of both seas in the ancient world. 



Somewhat to the south of the promontory, there are seen in 

 the inlet of Tjukkaragan. hills of the same height, composed of 

 the same tertiary limestone. The shell-limestone contains here 



• At least I have never found these (Serpulae) any where, neither did Pal- 

 las ; although S. G. Gmelin mentions (in his Travels, iiL p. 248) Serpula tri. 

 quetra and conglomerata as living in the Caspian Sea ; but thej are as little 

 found there as the shell which he names Chama cor. 



