./. I>. Dana — Archa item V. America, 381 



the Cambrian to the Carboniferous are identified l»v fossils for 

 300 mill's in Newfoundland* (the Carboniferous through the 

 southern half of the 300 miles), and also, for the western mar- 

 gin of the trough, in New Brunswick-Maine and in Massachu- 

 - Rhode Island; the outcrops of Lower Silurian to De- 

 vonian extending along the coast region of Maine for fifty 

 miles or more, <>r at least to Narraguagas Bay in Millbridge.f 



The length of the Acadian trougn between the limits stated is 

 about 1000 miles, and between the most northern and southern 

 localities of coal over 800 miles. It was probably therefore, a 

 it feature in the Carboniferous history of Paleozoic North 

 America: and it is a relatively small one in existing coal areas 

 only because of the vast amount of erosion which lias since 

 taken place — a large part of it, probably, after the epoch of 

 disturbance at the close of Paleozoic time. 



The continuation of the Coal measures and associated rocks 

 fr.»m southern Newfoundland in a line toward White Bay 

 proves that the Acadian trough extends by the east side of the 

 northern section of "Long Range, 1 ' and that the country on 

 the west Bide is not its proper continuation. The latter be- 

 comes to the north the Belleile Straits or trough, and in it 

 the rocks are Lower Silurian and older, like those of the lower 

 part of the St. Lawrence trough. 



D. Between Ranges IV and V, The Exploits River 

 Trough, extending along Exploits River across Newfound- 

 land, southwestward, to La Poile Bay and White Bear River, 

 the length 200 miles, containing rocks reported by the Can- 

 adian Survey to the Upper Silurian, 



There may be, also, the partially independent (E) Trinity — 

 Placentia and (F) Conception — St. Mary troughs, the borders 

 of which have afforded Cambrian fossils; and perhaps a sub- 

 ordinate Fortune Bay trough. 



[n view of the great extent of the Newfoundland Banks, 

 and the possibilities attributable to erosion, our knowledge is 

 very uncertain as to the loss in size and in fossiliferous strata 

 which may have taken place in eastern Newfoundland. The 

 shallow water area to the southeast, out to the 100-fathom 

 line, is much larger than all Newfoundland, and the distance 



$50 miles to the 50-fathom line, the outline of the Banks 

 pro] 



* Murray mentions in his Report of 18G6, the discovery of Olenellus Vermon- 



oat ;it the entrance to Long Arm, of Canada Bay, (about 



latil r/ 1. with Devonian beds (containing Prildphyton, Lepidodendron I 



//<'/■ - identified by Dawson) just north, at Cape Rouge Harbor. The 



near the west margin of the trough, the only part there extant. 



Mr. Murray, formerly of the Geological Survey of Canada, is the chief source of 



ourknowledg wfoundiand geolog 



. H. Hitchcock. Afrric. and Geol. of Maine. 1861, 1863; and on the vicinity 

 of Cobscook Bay, X. 8. Shaler, Am. J. Sci, xxxii. :'.5. 1886. 



