Geology of the Environs of Petersburg . 
435 
Their present perishable appearance is not so great an obstacle ta 
this supposition as might at first be imagined ; since this rock is 
extremely hard when in situ . The difference of hardness and 
colour observable in the rolled fragments may therefore be the 
effect of weathering. 
On the Ishora, the rolled pieces of different varieties of the 
intermediate bed become more frequent. In a dry ravine close to 
the village of Samsonovsky,* are found in the diluvian gravel, 
almost every description of boulder known in the country. Among 
them are round balls of the grey slaty clay of the upper part of the 
intermediate beds, a substance which hardly seems ever to have had 
sufficient solidity to withstand the shocks to which it must have 
been exposed in the diluvian current, especially in the company of 
the much harder pebbles by which these masses are surrounded. 
Since the period of their being lodged in this spot, they seem to 
have undergone considerable disintegration : although their outline 
is entire, as they are seen wedged in with the rest of the pebbles 
composing this gravel, not one of them could be taken out whole ; 
they are all now splitting in the direction of their laminse, and 
would fall to pieces as easily as the small rounded fragments of the 
same substance which are found in the brooks immediately beneath 
their parent rock. 
Near Anteleva, the gravel pits of Repolova deserve attention far 
the fine blocks of the large chamite bed which they contain, and 
which have been already described. 
* In Finnish Oloseen Mekky. As a great many of the villages retain their old Finnish 
names, even although they have received others from the Russians, I have thought if 
adviseable to give both, as the Fins will not always acknowledge the Russian names for 
villages inhabited exclusively by their own nation. 
