457 
Geology of the Environs of Petersburg . 
I shall conclude with stating, for the information of the future 
geological traveller in the north, what I consider the principal 
desiderata in the history of the formations in the neighbourhood of 
Petersburg. It would be necessary to commence by visiting those 
localities I have before enumerated, in order to acquire the requisite 
acquaintance with the characters of the strata : a work of no great 
length of time, and which I have been the more particular in 
pointing out, because, were they to be blindly hunted after throughout 
a tract of country so generally uninteresting as the greater part of 
the environs of Petersburg, and which gives so seldom the least 
clue to its hidden treasures, not only would more time be uselessly 
consumed than is usually at the disposal of those who are not 
residents in the capital, but many would be turned back by an 
early disappointment from researches of the highest importance to 
the geological history of Russia. 
One of the first objects is to trace accurately the outcrop of the 
limestone fromNicolskoyon theTosna, eastward behind Schlusselburg 
to Poutyelova, the nearest known point in that direction. In so 
doing, the rivers Mga, Moika, &c. will be the places most likely to 
exhibit natural sections, and their banks, I doubt not, will be found 
equally interesting, if not equally beautiful, with those of the 
Ishora and Tosna. Of course, if such researches can be prolonged 
beyond Poutyelova and the Sas, much information cannot fail to be 
collected. The southern outline of the limestone along the vale of 
Novgorod ; its prolongation westward through a part of the goot 
of Pscov, and the north of Livonia and Esthonia will also afford 
ample space for the labours of a geological investigator. It will 
also be useful to follow the northern escarpment from the vale of 
Ropsha by Gastilitzi and Capone towards the falls of Narva ; in 
doing which, an opportunity will offer of proving whether outliers 
3 M 2 
