TRIASSIC PERIOD. 



419 



their forest-vegetation of Conifers, Cycads, and Ferns, from which 

 old trunks and leaves were occasionally swept into the estuaries, 

 while the marshes were in some places accumulating vegetable 

 debris and forming coal. 



Characteristic Species. 



Conifers. — The genus Voltzia, near the Cypress, has lax leaves, with the 

 terminal often longer than the others; the fruit-branchlet consisted of broad 



s. 626-630. 



Fig. 626, Podozamites lanceolatus ; 627, Pterophyllum graminioides ; 628, Clathropteris 

 rectiusculus ; 629, Pecopteris Stuttgartensis ; 630, Cyclopteris Lirmasifolia. 



and short leaves or scales. A species near V. heterophylla (fig. 652) has been 

 found in the American rocks. One was found at the Little Falls of the Passaic, 

 in New Jersey. Several Fir-cones, six inches long, have been found at Phoe- 

 nixville, Pa., and a small one, from the Massachusetts beds, has been figured 

 by Hitchcock. 



Cycads. — The Pterophyllum longifolium Braun, from North Carolina and 

 Pennsylvania, is characteristic of the Upper Trias in Europe ; the species 

 resembles fig. 653; Pterophyllum graminioides, fig. 627, is another North Caro- 



