418 



MESOZOIC TIME — REPTILIAN AGE. 



1. Plants. 



The vegetation of the Triassic period includes no species of 

 Sigillaria, Stigmaria, or Lepidodendron, characteristic genera of the 

 Carboniferous era; but instead there are Cycads* along with 

 many new forms of Ferns, Equiseta, and Conifers. The figures 

 beyond show this contrast between the flora of the Carboniferous 

 and Triassic eras. Figures 626 and 627 represent the remains of 

 leaves of some of the Cycads ; figs. 652 and 652 a, one of the Coni- 

 fers, a Voltzia related to the Cypress ; and figs. 628, 629, and 630 are 

 species of ferns. Trunks of Conifers occur occasionally in the 

 sandstone. One found near Bristol, Ct., was fifteen or more feet 

 long and one foot in diameter. No species of grass or moss have 

 been met with. Many plants of remarkable forms found in Con- 

 necticut and Pennsylvania remain to be described. 



The remains of plants are sufficient to show that the hills had 



* Grymnosperins (p. 166) are divided into (1) Conifers, comprising the Pine, 

 Spruce, Hemlock, etc.; (2) Sigillarids, the Sigillarise of the Palaeozoic; (3) 

 Cycads, the plants above alluded to, of which the two most prominent groups 

 are named Cycas and Zamia. 



The Cycads, while related to the Conifers in structure and fructification, are 

 totally different in habit. They have a simple trunk, with a tuft of large 

 leaves or fronds at top, and thus 



much resemble a Tree-fern or young Fig. 625. 



Palm. The fronds unroll in expand- 

 ing, as in the Ferns, but their form 

 is closely like that of many Palms. 

 Yet, while resembling palm-leaves in 

 shape, the leaflets have no tendency to 

 split longitudinally, as in that tribe. 

 Fig. 625 a represents a trunk of a short 

 extinct species, a foot and a half in 

 diameter, and 625 b one of the long 

 fronds from the graceful cluster that 

 crowns the top in a Zamia ; both are 

 very much reduced in size. The 

 species of Cycas are sometimes 30 

 feet high, but those of Zamia are 

 usually short, seldom exceeding 3 or 

 4 feet. The existing species are con- 

 fined to warm climates, occurring in 

 the West Indies, Mexico, and equatorial South America; in southern Africa 

 and Madagascar; in southern Asia, Japan, and the East Indies; and in 

 Australia. 



