104 CONTRIBUTIONS TO THE GEOLOGY OF MAINE. [bull. 165. 
of 1861 were rendered necessary by new data furnished by the New 
Hampshire and New Brunswick surveys. This is the only complete 
geologic map of Maine that has been published. 
As explained elsewhere, there is an intimate connection between the 
geology of Maine and that of New Brunswick and Quebec, and accord- 
ingly the investigations in the Canadian provinces have thrown consid- 
erable light on geologic problems in Maine. On the other hand, many 
facts are better exhibited in Maine, and the New Brunswick survey has 
found it advisable to conduct some field operations along the Aroostook 
River and the Fish River Lakes. 1 Prof. L. W. Bailey has had many 
years' experience in dealing with the complicated problem presented 
by the New Brunswick formations, and has given the benefit of this 
experience in his discussion of the similar geologic conditions of Maine. 
The above-mentioned papers comprise all the material directly relat- 
ing to the geology of northeast Maine. Much more work has been 
done on the coast line and many contributions of value have been 
made, especially in regard to the surface geology and the petrography 
of those parts which have been mapped. 2 At present the relation 
between the geology of southern and northern Maine has not been 
determined, and these parts of the State must be treated as two distinct 
areas. 
1 The results of these excursions are given in the Transactions of the Royal Society of Canada and 
in the Reports of the Geological Survey of Canada. Three papers in particular, from the pen of Prof. 
L. W. Bailey, are of great value for the interpretation of the stratigraphy of the region, viz: 
On the Silurian system of northern Maine, New Brunswick and Quebec: Trans. Roy. Soc. Canada, 
Vol. IV, 1887, Sec. IV, pp. 35-41. 
Notes on the physiography and geology of Aroostook County, Maine: Trans. Roy. Soc. Canada, 
Vol. V, 1888, Sec. IV, pp. 39-44. 
On some relations between the geology of eastern Maine and New Brunswick: Trans. Roy. Soc. 
Canada, Vol. VII, 1890, Sec. IV, pp. 57-68. 
The substance of these papers may be found also in Reports of Geological Survey, Canada, 1886-1893. 
2 The papers of recent years, especially those of Shaler, Davis, Crosby, Stone, Dodge and Beecher, 
Kemp, Bayley, and Smith are especially valuable. 
