•iv GEOLOGY. 



land, where this rock has been pointed out to me, though it would be superfluous for 

 me to describe what is well known to every geologist. And if sometimes pure and 

 somewhat marble-like in its texture, so it is argillaceous and dull, when it approaches 

 to those shales into which it gradually passes, and with which it is interstratified. 



It is in its shales also, as I understand is usual with all limestones, that the organic 

 remains which it contains are chiefly found ; though, as is not uncommon elsewhere, 

 some of these occur only in that compact and almost pure calcareous rock, of which 

 they form a part. If, even, I were better informed on this subject, so as to know the 

 distinctions of rocks which are derivable from shells, I could not pretend to dis^ 

 tinguish fragments, nor even the more perfect shells, by their present names in the mo- 

 dem systems ; since I have had no means of keeping my knowledge up to the level of 

 the improvements in this branch of science. Suffice it to say, that such organic 

 remains, or shells, as I found, consisted of corals, of entrochi, of tetebratulae, and of 

 others which I will not, or need not, pretend to name ; as of all I may say, that they 

 bore such a general resemblance to those of the " mountain limestone " of England 

 and Scotland, which I have seen in collections, as will doubtless satisfy others respect^^ 

 ing that in which I am not inclined to take any further concern than may be necessary 

 for allowing others to form those conclusions, which it would be presumptuous in me to 

 draw. 



To terminate the history of this limestone, I need only remark in addition, that after 

 ceasing at Port Logan, where the primary rocks reach the shore, it recurs at Neitchillee, 

 to the southward of the isthmus of Boothia, and that it was thence traced for about two 

 hundred miles to the westward, towards Cape Franklin, where our kno vledge of 

 this coast ends. On this long line, however, no mountains of this rock, such as I have 

 described as occupying so great a range of country, occurred. In general, the shores 

 were barely skirted by low strata of a calcareous stone, frequently schistose, intermixed 

 with shales ; as they were often so encumbered with fragments and blocks of the 

 primary rocks, as well as of the limestone in question, that I could not often be sure 

 that the fundamental strata were present. The geological conclusion that I was com- 

 pelled to draw was, nevertheless, the same ; namely, that the primary district of this 

 portion of the American coast was skirted throughout its whole extent, with the excep- 

 tion of that line on which the sea met those rocks, by a series of secondary strata, of 

 which this peculiar limestone was the leading and almost the exclusive member. 



I ought now, according to the usual doctrines of geology, as I understand them, to 

 have also found the red sandstone, which holds a place between this limestone and the 

 primary srtata. I must, however, observe, that on the whole of the long line which I 

 examined at various times, extending from Northeast Cape to the Western Sea, that 



