524 PHYSICAL GEOGRAPHY. 



Mountain axis, both in Vermont and for a considerable distance into Canada, are the 

 same with the White Mountain series), and the White Mountain series. This address 

 seems to be the first place where the author uses the term White Mountain series to 

 apply to a system of rocks, and he evidently intends that it shall take the place of the 

 name of Terranovan (p. 33). Dr. Hunt, in this address, clearly states that he believes 

 this series of rocks to be both pre-Silurian and pre-Cambrian in age ; and I owe him 

 an apology for quoting him, on one occasion, as having called them Cambrian in this 

 address. My only excuse is the impression derived from his letter of the previous 

 year, that he considered the White Mountain series the equivalent of the rocks in 

 Newfoundland carrying Potsdam fossils, and my inability to be present during the 

 delivery of the Indianapolis address. 



It will be observed that the definition of White Mountain series, given in this ad- 

 dress, corresponds with mine of the previous year, even to including the porphyritic 

 gneiss, as respects the older strata, but differs by including the equivalents of the Cob's 

 group with the older series. Subsequently Dr. Hunt suggested the use of the adjective 

 Montalban instead of White Mountain. 



I have presented these statements for two reasons, first, to correct a misapprehen- 

 sion of Dr. Hunt, stated in public on two occasions, in reference to the question who 

 first assigned the White Mountain rocks to their proper place beneath the Cambrian ; 

 and, second, to justify myself, as the originator of the term White Mountain series, in 

 restricting its application, and returning to an older name for the large division, first 

 suggested in 1835. 



In the Proceedings of the American Association for the Advancement of Science, vol. 

 xxii, p. 116, after expressing the opinion that the White Mountain rocks are pre-Cam- 

 brian in age, Dr. Hunt says, "this view is, I believe, adopted by Prof. Hitchcock." 

 A similar expression is made use of in the Proceedings of the Boston Society of Natural 

 History, vol. xv, p. 310. It would appear, however, from the historical statements 

 given above, that Dr. Hunt, rather than the author, has "adopted" this view. It is 

 to be presumed that both of us arrived at the same conclusion independently of 

 each other ; while it is to the credit of the New Hampshire geologist that his official 

 report contained the first announcement of the use of a term derived from the geog- 

 raphy of his field of labor. That this new use of the name White Mountains should 

 be employed by so able an investigator as Dr. Hunt, only two years after its sugges- 

 tion in the state report, is confirmatory evidence of the appropriateness of the desig- 

 nation. 



In 1812 and 1817, William Maclure published geological maps of the United States, 

 on which is represented an area of "primitive rocks" extending from Maine to 

 Alabama, and including the Adirondack region. From the accompanying text it ap- 

 pears that these rocks are regarded as a formation, and as the oldest known in the 

 country. 



In 1835, G. W. Featherstonhaugh, in a report upon the "Elevated Country between 

 Missouri and Red Rivers," urged the necessity of giving a general name to the chain 



