CRETACEOUS PERIOD. 



459 



Sycamore), Hickory, Willoiv' (Fig. 828), Oak, Poplar, Maple, Beech, 

 Fig, or the genera Sassafras, Liriodendron, Platanus, Juglans, Salix y 

 Quercus, Populites, Acer, Fagus, Ficus. Leaves of Sassafras, Tulip- 

 tree, and Willow are common. There were also sj:>ecies of Redwood 

 (Sequoia), the genus to which the "Big Trees" of California belong. 

 There were also the first of the Palms. Fossil palm-leaves, of the 

 genus Sabal, are met with on Vancouver's Island, in deposits which 

 have been pronounced Cretaceous. 



Coccoliths, calcareous disks less than a hundredth of an inch in 

 diameter (p. 135), which are now common over the bottom of the 

 deep oceans, contributed to the Cretaceous limestones, though not yet 

 recognized among the fossils of the American beds. 



Fig. 825, Sassafras Cretaceum Newb., from the Dakota group, along with the three 

 following (Meek & Hayden); Fig. 826, Liriodendron Meekii Heer; Fig. 827, Legumi- 



Figs. 825-828. 



Angiosperms 



(or Dicotyledons). — Fig. 825, Sassafras Cretaceum; 826, Liriodendron Meekii;. 

 827, Leguminosites Marcouanus ; 828, Salix Meekii. 



nosites Marcouanus Heer; Fig. 828, Salix Meekii Newb. Large stumps of Cycads have 

 been found in Maryland, near Baltimore ; one is twelve inches in diameter and fifteen 

 high. (P. T. Tyson). 



The Cretaceous species of Platanus are mostly analogous to P. aceroides. Other spe- 

 cies from Kansas or Nebraska, Acer obtusilobum Lsqx., Sequoia Reichenbachi Heer, Se- 

 quoia formosa Lsqx., Liquidambar integrifolius Lsqx., Pojmlites fagifolia Lsqx., Ficus 



