168 INDEX 



*>age. 



Strata, correspondence of, on the sides of streams and valleys - . 15 



Systematic succession of - - - 15 



Inorganic - - - - 16 



Organic and aqueous origin of - - - 16 



Causes of their deficiency - 20 



T. 



Tertiary order - . - 59 



Localities in the United States . . 62 



Basin of Paris . 89 



Quadrupeds and vegetation of - 90 



Trap, an intrusive rock - 17 



Curious exhibition of - 17 



Trempe a 1'Eau, description of - - , 129 



U. 



Unios, fossil, associated with coal plants - 111 



In the alluvial soil - 117 



Recent, Wisconsin 123 



Do. St. Peter's - 14.& 



V. 



Veins, mineral . 70 



Their nature - -71 



Clay found in copper veins . 72 



Metallic, general course of, in the United States . 73 



Sulphuret of lead in Missouri - . 74 



Flat veins . 75 



At Congo Soco - . 77 



Sulphuret of lead at Dubuque's and Galena 158 



W. 



Wealden group, deficient in the United States - - 57 



Its remarkable organic remains , 86 



Western waters, lowering of their ancient level - 117 



Do. do. - . 122 



Proofs of - - 124 



Wills's mountain, near Cumberland, Maryland, description of - 104 



Z. 



Zizania aquatica, or wild rice, remarkable extent of - - 121 



