NATURAL SCIENCES OF PHILADELPHIA. 127 



New Jersy Section compiled from tue Reports of that State. 



Green Sand. 60 ft. 



" The sand between the second and third beds has usually been 

 confounded with beach sand, which it closely resembles." 45 or 50 ft. 



Yellow limestone. 



Green Sand, Scapkites Conradi, Baculites ovatus, Ammonites 

 placenta. 45 or 50 ft. 



Sand " much colored with oxyd of iron, and when sufficiently 

 firm is found almost full of the impressions of shells." Belemnites 

 mucronatus. 65 or 70 ft. 



^» 



Green Sand, Nautilus Dekayi, Baculites ovatus, Belemnites mucro- 

 natus, and bones of Mosasaurus. 50 ft. 



Dark clays with "occasional streaks and irregular spots of green 

 sand." Ammonites placenta, Baculites ovatus, ^'c. ^-c. 130 ft. 



Dark blue, ash colored, and whitish clays, and micaceous sand, 

 with thin seams of coal. Gfeat quantities of sulphuret of iron 

 " Fossil wood is found in some of the layers in large quantities, and 

 some very distinct impressions of net-veined leaves were examined 

 in the clay at French's landing." 130 ft. or more. 



By comparing the foregoing sections with the following general section of the 

 Nebraska rocks, tlie parallelism between the formations, so far as the Cretaceous 

 rocks of the North West are represented in Alabama and New Jersey, will be 

 at once understood. 



In the following section of Nebraska rocks it will be observed we have placed 

 together all the Tertiary deposits known to us, without intending to express 

 any opinion in regard to the comparative ages of these formations. We have 

 also written in the column opposite them the word "Miocene;" this, so far as the 

 Judith River fresh water and Estuary formations are concerned, is done pro- 

 visionally. We have likewise made three subdivisions of formation No. 3. 

 This latter change is made mainly upon lithological ditferences between what 

 we regard as probably subordinate members of the same formation. The upper 

 or dark bed of very fine argillaceous matter, passes both downwards, and at 

 some points, horizontally into the gray marl below it, and appears to be local, 

 while the gray marl, in its turn, passes imperceptibly into the light colored 

 limestone below. 



It is due to the lamented Mr. Nicollet that we should state here, he saw the 

 two beds above mentioned, and noticed their differences in his report ; but in 

 consequence of the fact that he referred the Inoceramus occurring in the lime- 

 stone {[. prohkmaticus) to /. Barabini, a fossil not known below No. 4 and 5 of 

 the section, if indeed it occurs at all in the Nebraska beds, we were always at 

 a loss to understand his section. In addition to this, neither of us had ever 

 visited localities where this bed or the dark deposit forming the upper part of 

 No. 3 is exposed, previous to the late explorations. 



1857.] 



