G. II. Stone — Wind Action in Maine. 133 



in the layers of the sandy limestone. It is very probable that the Potsdam may 

 now be farther traced across the Hudson River somewhere near Marlborough. 



In Plate YI will be found a small map showing the entire extent of the fault 

 above described. 



It is proper to state here that I have strong reason to suspect the presence of a par- 

 allel belt of Potsdam limestone, more than a mile to the east of the present one, in 

 the most eastern of the three belts of limestone. The particular locality which has 

 furnished grounds for the above statement is on the summit of the ridge about 

 half a mile southerly from the mansion on the MacPherson (late Boardman) place. 

 The rock corresponds closely in its lithological characters with that of the Smiley 

 locality. I have found here but a single fossil — about half of one valve of a 

 brachiopod, which as far as it goes corresponds perfectly with Lingulepis pinniformis. 

 I believe it to be this fossil, and that consequently the rock is Primordial, but 

 cannot say that the evidence is absolutely conclusive. 



Explanation of Plate. 



A, Hill of f ossiferous Potsdam on Smiley's farm. 



B, Hill of Potsdam, partially conglomerate, on Smiley's farm. 



D, C, extensions of hill B. D is largely conglomerate. 



E, Hill containing much fine-grained, blue, thinly fissile calcareous shale of the 



Potsdam group : a few specimens of Lingulepis pinniformis have been found 

 here. 



F, Calcareous quartzyte, Potsdam group. 



The lane between the wall and fence just south of the hills E and F is the 

 southern boundary of Mr. Smiley's farm; at present date no Potsdam fossils, ex- 

 cept stromatocerium, have been found in this belt south of this line. 



G, one of the best localities for inspecting the Potsdam limestone and calcareous 



shale composing this long hill. Stromatocerium is found here. From the 

 summit of this hill a good view is presented of the wide plain of Hudson 

 River shale which extends westward from its base. 



H, a small quarry of arenaceous limestone apparently Potsdam, in the field be- 

 longing to W. S. Johnston. 



I, a high ridge of light- and dark-colored limestones, well exhibited at the spring 

 here indicated ; horizon of the rocks doubtful. 



K, outcrops of Hudson River shale at the surface of the ground within a few feet 

 of the Potsdam hill B. 



L, small quarry of compact, gritty layers of the Hudson River group, dipping at a 

 low angle. 



0, hilly outcrops of Hudson River shale in field north of the driving park. 



M, (in small included map), molding sand, and dock. 



T, (in small included map), outcrops of fossiliferous Trenton on the eastern mar- 

 gin of this limestone belt. 



Art. XIII. — Wind Action in Maine; by George H. Stone. 



Drifting sands of the ordinary type are very common in 

 Maine, especially in the western half of the State. These 

 sands are partly of marine, partly of fresh-water deposition. 

 All of the large rivers of Maine, except the Penobscot, covered 

 large areas with sand near where they emptied into the sea 

 during the Champlain epoch, the sea of that period being, as is 

 well known, somewhat more than 200 feet above its present 

 level. For various reasons the drift of the Penobscot valley 

 differed considerably from the valley-drift of any other large 



