68 THE CAMBRIAN. (bull. 81. 



MAINE. 



When describing the quartz rock of Bar Harbor, Mount Desert 

 Island, Prof. C. D. Hitchcock 1 suggested a Lower Silurian age for the 

 siliceous slates associated with the coarse sandstone or quartz rock, 

 by comparison with similar rocks on Flint Island, of which he had 

 stated that the correlation was more from fancy than real argument, 

 because it reminded him so much of the Potsdam sandstone in its ex- 

 ternal appearance. 



At a later date he says:* 



The first rock is a sandstone a't Bar Harbor, dipping at au angle of twelve degrees. 

 Ripple marks cover the surface of many layers, and curious cylindrical stems tantalize 

 us by their resemblance to fossils. The formation is probably of Cambrian age. 



The strata included under the title of " Cambrian " about Portland, 

 Maine, is described by Prof. Hitchcock 3 as follows: 



These rocks crop out in Saco, a dozen miles west. They are clay slates and indu- 

 rated argillaceous schists, the latter having a northwest strike, while the rocks of the 

 older series run northeasterly. These rocks are in character and position allied to 

 the Cambrian Paradoxides slates of Massachusetts, and exist in immense mass along 

 the coast of Maine west of Saco, and in New Hampshire. 



The correlation of these beds is based entirely upon their lithological 

 characters, as no mention is made of any fossils having been found in 

 them. 



In his account of the geology about Frenchman's Bay, on the coast 

 of Maine, Dr. W. O. Crosby describes the slate formation. The pre- 

 vailing rock is a compact and well jointed argillite or clay slate, of 

 black, drab, and purple tints, with distinct stratification. The author 

 concluded that these rocks are the newest rocks on this part of the 

 coast, by their relations in dip and distribution to the present contours 

 of the land; by their uncrystalline character; by their relations to the 

 iatrusives; by the fossils which they contain. The latter he describes 

 as smoothly and even gracefully curved semi-cylindrical grooves and 

 ridges about a line in diameter; they are often a foot or two in length, 

 and might sometimes be regarded as annelid trails, but in other cases 

 they are irregularly brauched in a way that would be impossible with 

 worm-grooves, but is very suggestive of smooth, slender fucoids. 4 The 

 general conclusion reached was that the Frenchman's Bay series be- 

 longed somewhere between the top and bottom of the Cambrian, with 

 the chances in favor of its being near the latter. In other words, his 

 observations tended to corroborate the suggestion made by Prof. Hitch- 

 cock twenty years before. He further states : 



1 Reports on the Geology of Maine. Second annual report on the natural history and geology of 

 Maine. A ugusta, 1862, pp. 269-271. 



2 Geology of Now Hampshire. Concord, 1877, vol.2, p. 32. 



•The geology of Portland. Am. Assoc. Proc, vol. 22, pt. 2, 1873, p. 168. 



♦Geology of Frenchman's Bay, Maine. Boston Soc. Nat. Hist., Proc, vol. 21, 1881, pp. 111-116. Geol- 

 of Frenchman's Bay, Maine, j ust east of Mount Desert Island. Ana. Jour. Sci., 3d ser., vol. 23, 1882, p. 64. 



