842 



HISTORICAL GEOLOGY. 



specimens of this species have been found measuring more than two feet in 

 diameter. 



Among the more or less uncoiled Ammonoids there are : Fig. 1395, the 

 Scaphites, S. Conradi, from the Fox Hills group, which is sometimes six feet 



1393-1400. 



1393 



Cephaxopods. — Fig. 18&3, Belemnitella Americana; 1394, a, b, Placenticeras (Ammonites) placenta; 1395, 

 Scaphites Conradi ; 1396, S. larvasformis ; 1397, 1897 a, Baculites ovatus ; 1398, young stage of B. com- 

 pressus ; 139S a, same, %vith outer laj-er of shell removed, showing sutm-es ; 1399, section of B. compressus, 

 reduced ; 1400, jSTautilus Dekayi. Figs. 1893-1897, 1899, 1400, Meek ; 1898, 1898 a, A. P. Brown. 



