PLANTS OF THE COAL. 



365 



Fig. 485. 



Fig. 486. 



Fig. 48? 



Figs. 485-487.— Coal-Ferns : 485. Leaf Scars of Pala;opteris, x J (after Dawson). 486. Leaf-Scar of 

 Megaphyton, x £ (after Dawson). 487. Caulopteris prirneva, showing Leaf-Scars. 



3. Lepidodendrids. — These are so called from the 13-pical genus 

 Lepidodendron. We will describe only this genus. 



Lepidodendrons are found most commonly in flattened masses rep- 

 resenting portions of the trunk or branches, very regularly marked in 

 rhomboidal pattern, and much resembling the 

 impression of the scaly surface of a Ganoid 

 fish. The name Lepidodendron (scale-tree) 

 is derived from this fact (Figs. 489 to 491). 

 These marks are the scars of the regularly-ar- 

 ranged and crowded leaves. All portions of 

 the plant, however, viz., the roots, the trunk, 

 the branches, the leaves, and the fruit, have 

 been found in abundance. From these the 

 general appearance of the tree has been ap- 

 proximately reconstructed. Imagine, then, a 

 tree two to four feet in diameter at base, forty 

 to sixty feet high, with wide-spreading roots, 

 well adapted for support on a swampy soil ; 

 the surface of the trunk and branches regu- 

 larly marked in rhomboidal pattern, repre- 

 senting the phyllotaxis; the trunk dividing 

 and subdividing, but not profusely, into 

 branches which are thickly clothed with scale- 

 like, or spine-like, or needle-like leaves (Figs. 

 492 and 494), and terminated by a club-shaped extremity (Figs. 493, 

 495, and 496) like the terminal cones of some conifers, or still more 

 like the club-shaped extremities of club-moss branches — and we will 

 have a tolerably correct idea of the Lepidodendron. 



Fig. 488.— Restoration of a Lepi- 

 dodendron, by Dawson. 



