268 Cincinnati Society of Natural History. 



The deposits in which these terraces have been worn consist of clay, 

 containino" marine shells, among which are Tellina groenlandica, T. 

 calcarea, Saxicava rugicsa, Nucula, Venus, Mytilus, and Balanus. 

 These shells were found as high as 390 feet above the hay. At Little 

 Malbaie there are six terraces, plainl}' distinguishable, one above 

 another. 



T. A; Convad* described, from the Eocene of Georgia, Mitra 

 georgiana, Catopygus conradi, now Cassidulus conradi^ Holaster 

 mortoni^ JSFucleolites lyelli., Discoidea haldemani, and Cidarites 

 mortoni. Robert W. Gibbes described, from the Eocene of Ashley 

 river, Myliobates holmesi. And Zadock Thompsonf described, from 

 the drift in Vermont, exposed in excavating for the Rutland and 

 Burlino-ton railroad, Delphinus vermontanus, now Beluga vermon- 

 tana. 



In 1851, Philip T. TysonJ described the Sacramento Valley as 

 a Ion o" prairie, occup3'ing the space between the flanks of the Sierra 

 Nevada and those of the Coast Range, closed in on the north b}' the 

 terminal spurs of the Cascade mountains, and on the south by the 

 junction of the Coast Range with the Sierra Nevada. Its greatest 

 width is less than 60 miles, but it maintains a mean width of nearly 

 50 miles throughout almost its entire length. The surface strata are 

 not older than the Eocene or Miocene, and rest immediatel}^ upon the 

 metamorphic and hypogene rocks. 



Prof. James Robbg showed the direction of the Drift stride in New 

 Brunswick to be, generally, about 10 deg. W. of true north to 10 deg. 

 E. ot south, but that some striae have a direction N. 30 deg. E. Others 

 N. 45 deg. W., and still others east and west. 



T. T. Bouve|| described, from the Eocene of Georgia, Catopygus pa- 

 telliformis, now Cassidulus patelliformis, and Hemiaster conradi. 



In L852, Mr. J. Evans^ explored that region of the Upper Missouri 

 countr}^, lying high upon White river, called the " Mauvaises Terres^'' 

 or "Bad Lands." He said that from the high prairies, which rise in the 

 back, by a series of terraces or benches toward the spurs of the Rocky 

 Mountains, the traveler looks down into an extensive valle}^ that may 

 be said to constitute a world of its own, and which appears to have 

 been formed partly by an extensive vertical fault, and parti}' by the 

 Ions: continued influence of the scoooinor action of denudation. 



* Jour. Acad. Nat. Sci., 2d ser., vol. ii. 

 f Am. Jovir. Sci. and Arts, 2d ser., vol. ix. 

 t Geo. and Ind. Resources of Cal. 

 % Proc. Am. Ass. Ad. Sci., 4th Meeting. 

 II Proc. Bost. Soc. Nat. Hist., vol. iv. 

 IF Geo. Sur., Wis., Iowa and Minn. 



