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TABLE OF CONTENTS. 



assuming a ohronobgictil order in minerals, 448 ; in replying to Daka, Hunt 

 assorts that lie did not sav that the AVhite Mountain roclvs wore newer th;i.u 

 those of the Green Mountains, 449 ; it is shown, however, that he had said this, 

 450, 451 ; a comparison of Hunt's statements of what ho said witli wljat he 

 really did say, 452 ; Hunt's methods set forth, 453 ; Dana's eoinnii'iits on 

 some of Hunt's statements, 453, 454, 455. Dana remarks that Hunt's volume 

 "contains a series of misrepresentations of the views of others wholly unueeessary 

 and dillieult to find excuse for," 454 ; Dana's examination of the Helderberg 

 rocks in the Connectieut Valley, with reference to the (question whether th(i age 

 of strata can be determined by means of the minerals they contain, 454, 455; 

 " lithological evidence worso than worthless," 455. Selwyn's opinion of the 

 revolution in Hunt's views, 455 ; metamorplusm and mhieralization no test of 

 geological age, 455. LKSLr.Y, in 1875, states that in Pennsylvania the Huronian 

 or Green Mountain system overlies thu AVhite Mountain series, both being ohler 

 than the Totsdam, 455 ; Dana's criLicdsm of Lesley's statements, 456 ; Lesij^v, 

 in 1878, withdraws this opinion, and now considers that tiie Green Mountains 

 are Pahcozoic and the Wlutc M.ountains Devonian, 456. Dana (1877, 1879) 

 gives the results of his own and Wing's investigations in Vermont and W(.'ateru 

 M^assachusetts, 456, 457 ; according to these, the Hmestones of tluit region are 

 wholly Lower Silurian, and the Taeonic slates overlie them, and are of the nge 

 of the Hudson lUver grou]), 457. Hunt, in 1878, further develoi)s his views 

 in r(!gard to the Upper and Lower Taconie series, 457, 458. Hunt, in 1879, 

 jives tlie reasons why he formerly referred the Green Mountain rocks to the 

 Quebec group, when he in fact regarded them as Hurouian, 458; " ofheiid 

 r(!asons " not oidy prevented his dissc-l^ng from Logan's vi(!ws, but caused him 

 to afTirm tlieir correctness in the strongest possible manner, 458'; further light 

 on Hunt's meUiods, 458. Various contradictory statements of C. 11. Hitch- 

 cock in regard to Vermont geology, 460, 461 ; in 1877 Im considers the Green 

 and the AA^hite Mountains *' nearer the Laurentiiut tiian the Huronian," iind in 

 1875 thinks that Emmons understood the relations of the rocks called by him 

 Ta(;onic "better than most of his contemporaries," 460, 461 ; in 1880 lu; finds 

 that he had been in accord with Dana and Wing for years in their "disbelief in 

 'Taconism,' " 400. In 1880 and 1881, Dana brings together the evidence in 

 regard to the geological age of the Green Mountain limestones and associated 

 rocks, showing beyond possibility of doubt that they are Lower SUurian, 

 4G1, 462. 



NEAV YOIIK. 



Geology of the Adirondacks, 462, 463 ; Hall and Logan's views in 1864, 463. 

 Discovery of I'x)zobn iu Westchester County, 463. Hall on the relations of the 

 limestones of Northern New York, 463, 464. Lkeds, in 1877, on the lithology 

 of tlie Adirondacks, 464 ; his views criticised, 464. Diutton on the geology of 

 Richmond County, 464 ; insufficiency of his data, 465. 



^ 



NEW JERSEY. 



IL D. Rogers's views of the age of the gneiss and limestone of this State, 465. 

 Cook on the Azoic rocks, 465, 466; some suggestions in regard, to points 

 needing further examination, 466 ; origin of the iron ores, 466. 



