FORMATIONS AND PHYSICAL HISTORY 407 



Fig. 358. Map of Xo.-ih America showing the outcrops of tin- Hamilton forma- 

 tion and the general relations of land and water during the Hamilton epoch. The 

 black area at the north probably includes Lower and Upper Devonian as well as 

 Middle. Compare Figs. 356 and 357. The conventions are the same as in earlier 



