280 



PALEOZOIC TIME. 



like those preceding it in time, thins out in that direction, and thickens 

 toward the Hudson, being two or three thousand feet thick in the Cats- 

 kills. It stretches south along the Appalachian region, beneath the 

 Coal formation of Pennsylvania and Virginia, where it is 5,000 or 

 6,000 feet thick. It is eminently an Appalachian formation. 



II. Life. 



The rocks afford but few relics of life. The plants are related t<? 

 those of the preceding period. A portion of one large fern, Devonian 

 in character, is represented in Fig. 557 A ; and another of the same 



Figs. 557 B-560. 



558 



Fern. — Fig. 557 B, Cyclopteris minor. Fish Remains. —Fig. 558, scale of Holoptychius Ameri- 

 canus ; 559, tooth, id.; 559 a, section of tooth ; 560, scale of Bothriolepis Taylori. 



genus, in Fig. 557 B — a genus characteristic especially of the Devo- 

 nian (p. 271). There were also other ferns, besides Lepidodendra, 

 Sigillaria, Catamites, etc. 



Remains of large fishes occur in the beds. Figs. 558, 560 repre- 

 sent scales of two species, and 559, a tooth of the first of them. The 

 fish that had this tooth was a very large Ganoid, and resembled that 

 represented in Fig. 569, page 286. 



Characteristic Species. 



1. Plants. — The fern, of which a portion is represented in Fig. 557 A, was over a foot 

 broad; it was obtained at Montrose, Pa., by H. A. Riley. Cyclopteris minor (Nceggera- 

 ihia minor Lsqx.), Fig 557 B, is from Pottsville. Pa. 



