116 Crefacemis, 



In 1875, he described,* from the Ripley Group at Snow Hill, Greene 

 county, North Carolina, Anomia linifera^Eadula oxyplem^a, Trlgonarca 

 triquetra, T.umbonata, T. 2}erovaUs, T. carolinensis, T. congesta^ Ne- 

 modon hrevifrons, Barhatia carolinensis, B. Untea, Arcoperna carolin- 

 ensis^ Inoperna carolinensis^ Mytilvs condecoratus, 31. nasutns, Etea 

 carolinensis., Brachymeris alta, Crassatella carolinensis, C . x>teropsis^ 

 Arene carolinensis, Lucina glehnla,, Cardium carolinense, Protocardia 

 carolinensis, Aphrodina regia,Cyclothyris alta, C. carolinensis, Baroda 

 carolinensis, Oene x>lcina, Linearia carolinensis, Valeda lintea, Oypri- 

 meria depressa, Hercodon elUpticus, Cymella hella, Corbula caro- 

 linensis, C. hisulcata,C. perhrevis,G. suhgibhosa, Diploconcha cretacea, 

 Callonema carolinense, Leioderma thoracica., Liinatia carolinensis, 

 and from Cape Fear river, Corbula oxyriema, and Anomia lintea. 



The Cretaceous rocks,f corresponding in age with the great chalk 

 formations of Europe, though very different from them in mineral 

 character, are spread over a great extent of surface in the western part, 

 of British America. Except in a few localities, and those chiefly in 

 proximity to the Rocky Mountain region of uplift, they are still 

 almost as perfectly horizontal as when first deposited. The eastern 

 edge overlaps Silurian and Devonian beds, and runs nearl}- parallel 

 with the base of the Laurentiau range for a distance of about 130 

 miles, from the 53d to the 55th parallel of latitude. Southward it trends 

 to the East, and probably crosses the 4.9th parallel east of Red river; 

 while in southwestern Minnesota it reposes in some places directly 

 on granites which are no doubt Laurentiau. The general course of 

 the eastern outcrop is consequentl}^ about north-northeast; and it is 

 marked, broadly-, by a series of escarpments and elevations, including 

 — from south to north — Pembina, Duck, Porcupine and Basquia 

 Mountains. All these appear to be composed, for the most part, if 

 not entirely, of Cretaceous rocks, though the extreme edge of the 

 formation may often stretch beyond them. These mountains are, more 

 cori'ectly speaking, the salient points of the edge of the second plateau, 

 and the generally horizontal position of the beds thus suddenly cut 

 oflf to the east, attests the immense denudation which must have taken 

 place in modern times. North of the Basquia Mountain the edge of 

 the Cretaceous would appear to run westward and cross the Sas- 

 katchewan near Fort a la Corne, where, at Cole's Falls, a dark-colored 

 shale has been referred to the lowest member of the series. The 



* Geo. of N. Carolina, 1875. 



t Dawson's Rep. Geo., 49th Parallel, 1875. 



