MANUAL OF NATURAL HISTORY. 579 



shells, and gravel, and calcareous conglomerate ; the 

 organic remains consist of species generally resem- 

 bling those of existing forms. 



The Pliocene epoch is divided into the lower, in- 

 cluding the red crag of Suffolk, in which phospha- 

 tized bones and coprolites occur in great abundance ; 

 and the upper, or newer Pliocene, which includes 

 the red crag of Norfolk, in England, about half 

 the Island of Sicily, the blue clay of the Mediter- 

 ranean, and the argillaceous limestone around the 

 Caspian. 



The species of Mollusca of the newer Pliocene are 

 nearly identical with the recent species, while many 

 of the mammals belong to forms entirely lost ; the 

 species of fish of the Norfolk crag are mostly refer- 

 able to genera common in tropical seas. The upper 

 tertiary marine deposits exhibit many genera of 

 Polyzoa and of polypiferous animals, such as species 

 of Isis, Madrepora, Eschara, Nullipora, Flustra, 

 Meandrina, Turbinolia, and others. 



The plants of the tertiary formations consist of 

 Ferns, Pinacece in great numbers, Palms and tropi- 

 cal monocotyledons, Elms, Willows, Poplars, Ches- 

 nuts, and Sycamores ; Carpinus, Betula, Compto- 

 nia, and three species of the Walnut tribe. The 

 chief genera of the Pinacece, are Pinus, Taxites, 

 and Podocarpus, and among the family of Palms, 

 leaves of Flabellaria, Phcenicites, and Juniperites, 

 and the fruit of Cocos have been discovered ; and, 

 belonging to the Lily-tribe, those of A momocarpxvm 

 and Pandanocarpum. The bodies called " Gyro- 



cc 2 



