OF LABRADOR AND MAINE. 253 



Crepidula fornicata, abundant. Scalaria gronlandica, rare. 



Buceinum undatum, rather rare. Balanus rugosus, very abundant. 



plicosum, abundant. Serpula, forming a layer several feet thick. 



Nassa obsolete/,, abundant. Pagnrus pallicuris (claws). 

 trivittcda, abundant. 



" Now these are, without any exception, the same species that are found living on the 

 shore of Nantucket and Cape Cod ; and as they are all in their natural position, the bivalves 

 having almost always the two valves united, and the Venus being commonly half open, 

 just as they are found on the beaches when the muscles have relaxed after death, we may 

 fairly infer that in this part of the continent at least, the climate has not undergone any 

 considerable change since the deposition of these fossils. 



" The presence of a stratum of disintegrated shells of the same species, resting upon the 

 undisturbed oyster-bank, may easily be accounted for by a somewhat more violent action 

 of the tides, which deposited in this irregular manner a part of the shells which were 

 washed off from the oyster bank itself, in the same way as is the case now among the Nan- 

 tucket shoals. 



" Until last year it was assumed by the geologists of this country that there were no fos- 

 sils to be found in the drift, south of Lake Champlain and the State of Maine, when one of 

 us had the good fortune to discover several species in the drift of Brooklyn, near New 

 York. 1 Similar fragments, especially of Venus mercemria, have since been found in the 

 cliffs of Point Shirley, in Boston Harbor. Now, as the fossil shells in both places are of the 

 same species as those of Sancati cliff, there is every reason to consider them as belonging 

 to the same period, their more or less perfect state of preservation depending merely upon 

 local influences. It ought further to be stated, that wherever the shells are worn or 

 broken, and the strata which contain them coarse and irregular, it is either in such places 

 where the tidal currents must have been violent, so as to carry and deposit promiscu- 

 ously heavy pebbles and minute shells, as in the cliffs of Point Shirley ; or in such places 

 where we must suppose that floating ice was at work, carrying indiscriminately heavy ma- 

 terials, pebbles and boulders, together with oysters and other shells detached from the 

 neighboring flats, and heaping them up in the corners of bays and sounds. This seems to 

 have been the case with the coarse deposits of Brooklyn, where oysters and Venus are 

 generally found imbedded in a reddish loam intermixed with pebbles and boulders, many 

 of which are distinctly scratched, thus reminding us of similar actions which you have de- 

 scribed in Fundy Bay and in the St. Lawrence ; whilst in other places like Nantucket 

 and the bays and fiords of Maine, a more cpaiet action prevailed, so as to allow the shells 

 to be preserved in their natural place and position after death. 



"Finally, the fossils of the drift of Nantucket bear such a striking similarity to those of 

 the newer pliocene of the Southern States, that they become a natural link between the 

 northern and southern deposits. Instead of considering these as so many distinct forma- 

 tions, we should therefore henceforth look at them as mere modifications of the same de- 

 posit, being the result of the same agencies, viz. : oceanic tide-currents along the whole 

 coast of the United States, combined with gradual and secular oscillations of the whole 

 continent, the local strength of the tidal currents affording a sufficient explanation for local 

 diversity in the arrangement and size of the materials in each locality." 



1 E. Desor's Letter to M. de Verneuil, in the Bulletin de la lection of the drift fossils of Brooklyn has since been made by 

 Socicte Geulofjique de France, 1847. A most interesting col- Mr. Redfield. 



