74 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



rocks, — a period of important deformation that has also been de- 

 monstrated in Virginia. More localized areas of such upturning, 

 occurring at times not similarly occupied elsewhere, are represented 

 by the Acadian tract which was profoundly disturbed during the late 

 Devonian. These local foldings have, however, followed the same laws 

 of axial development that were obeyed in the more general mountain- 

 building, and have not interfered with the essential tectonic agreement 

 of the system. 



Thus a great generalization has been built up, in largest part by 

 structural studies, aided, of course, by palseontological evidence, and 

 by the lithological investigation of the sediments involved. Of late 

 years a fourth efficient means of further developing the conception has 

 been wrought out, simply by the recognition of the fact that sedi- 

 mentation has its correlative in denudation, and that the later forms of 

 subaerial erosion on unsubmerged areas may be expected to show similar- 

 ities wherever the conditions of erosion were equivalent along the major 

 axis of the system. The remarkable parallelism subsisting among the 

 forms of wasted land-surfaces in New England, in the New Jersey- 

 Pennsylvania region and in the southern Appalachians, has been 

 broadly sketched by Davis * and further emphasized by Willis, Hayes, 

 Campbell, Keith, and others. As yet the definite statement as to how 

 far this last method of correlation may be extended to the Acadian 

 division of the belt has not been made ; in the following pages it is 

 proposed to describe briefly and illustrate some of the more important 

 erosion-forms in Nova Scotia and the adjacent portions of New Bruns- 

 wick and to inquire into their interpretation. 



The field-work on which this sketch is based was . confined to a ten 

 days' tour on the main lines and branches of the Intercolonial and 

 Dominion Atlantic railways, supplemented by a second railroad trip 

 from Montreal to North Sydney and a cruise close inshore from Cape 

 Canso along the southern coast to Halifax, where the train was taken 

 for Yarmouth. Such rapid views of the country may possibly lead to 

 results of some value if they be checked and amplified by the study of 

 the detailed works published by governmental survey or by private 

 individuals. 



The lack of good topographic maps of the inland areas renders 

 the discussion difficult, and many interesting questions must on that 

 account be left untouched. The best cartographic data are derived 



1 The geological dates of origin of certain topographic forms on the Atlantic slope 

 of the United States. Bull. Geol. Soc. America, 1891, Vol. 2, p. 545. 



