406 NATURAL SCIENCE. dec, 



speak here. It is certainly obvious that this kind of investigation is- 

 what we want more of ; but it is also obvious that it can only be done 

 by those who, like Mr. Buckman, are palaeontological specialists, and 

 who are, like him, intimately acquainted with the district that they 

 are examining, and able to take advantage of every temporary 

 exposure. This is where our numerous local geologists and collectors 

 will find their opportunity. 



The Correlation of Geological Formations in America. 



The principles alluded to above are clearly not neglected 

 by our fellow-workers on the other side of the Atlantic. The 

 Geological Survey of the United States has issued a series of 

 " Bulletins " during the past few years dealing with the Correlation 

 of the Geological Formations of the United States. These bulletins- 

 (nos. 80, 1891, Devonian and Carboniferous; 81, 1891, Cambrian;. 

 82, 1891, Cretaceous ; 83, 1891, Eocene ; 84, 1892, Neocene ; 85,1892,. 

 Newark System ; 86, 1892, Archaean and Algonkin) are historical 

 studies of the classifications and nomenclatures of the formations, 

 made for the purpose of ascertaining how satisfactory correlations 

 have been made, and upon what principles they have been based. 

 The literature of the century has been reviewed, and various specific 

 problems have arisen for the solution of which it has been necessary 

 to determine the relations between standard formations already 

 named and classified and those newly discovered. The discussion of 

 each problem has been followed out in detail, the various attempts 

 at correlation have been noted, and the methods employed and the 

 final results attained have been traced to the principles involved in 

 their determination. 



We reproduce here the headings of researches dealt with in the 

 Devonian and Carboniferous monograph, as giving a good idea of 

 the amount of material rendered easily available to the geological 

 student. They are as follows : — 



(1) The general correlation of the Palaeozoic formations of 

 eastern North America with the corresponding formations of 

 Europe. 



(2) The determination of the parallelism between the upper 

 Palaeozoic formations of the Appalachian region and the rocks 

 of the interior of the continent as far west as the Mississippi 

 River. 



(3) The correlation of the northern Appalachian region with 

 the various subdivisions of the Coal-measures and formations 

 immediately underlying them. 



(4) The problems connected with the correlation of the 

 Chemung and Catskill groups, and with the correlation of the 

 Waverley and Marshall groups. 



