198 
THE GEOLOGIST. 
some of the ribs are displaced. Two or three vertebree, with 
fragments of the carapace^ or shield are very distinct. In 
clearing the stone Mr. B. expects to find more bones than 
are now visible. 
Relative Levels of the Caspian and Azoff Seas. — At the 
Paris Academy of Sciences^ a communication was received 
from M. Hommaire Dehel^ on the difference of the level 
between the Caspian Sea and the Sea of Azoff. Several 
scientific men have been charged by the Russian Government 
to ascertain the level between these two seas ; but the results 
have differed so much that a verification was necessary^ and 
this was undertaken by M. Hommaire Dehel^ in 1838; but 
it was not until September^ 1839, that he could establish his 
points of survey. M. Hommaire Dehel, now reports that 
18*30 metres is the difference of level between both seas. It 
results^, from the observations made by M. Hommaire Dehel 
on the shores of the three seas of Southern Hussia, at the 
mouths of the different rivers and streams in the steppes of 
Astrican, and at the Sea of Azoff, that the Caspian Sea had 
formerly a much higher level, and that it was united with the 
Black Sea, at a period anterior to any existing historical 
records. Already this idea as to the junction of the two seas 
has been maintained, but it was said that the Black Sea had 
become lower by piercing its way through the Bosphorus, 
and shedding its waters into the Sea of Marmora. The sink- 
ing of the Caspian Sea has been accounted for by the lower- 
ing of the basin, but M. Hommaire Dehel gives an 
explanation of this, which he conceives more natural, by ob- 
serving that the Caspian Sea has very few tributaries, and 
that a diminution in the waters of the Oural and the Volga 
has been a sufficient cause for the lowering of the level of this 
sea. 
