368 



PALEOZOIC SYSTEM OF ROCKS. 



4, Sigillarids, —The typical genus of this family is Sigillaria. 

 These plants are found, like Lepidodendrids, mostly as flattened masses, 

 which are portions of trunks, but also as roots and leaves. The trunk- 



FiG. 501. 



Fig. 503. 



Figs. 499-503.— Sigillarids: 499. Sigillaria reticulata (after Lesquereux). 500. Sigillaria Graseri. 

 501. Sigillaria laevigata (European). 502. Sigillaria obovata (after Lesquereux). 503. Leaf of 

 Sigillaria elegans (after Dawson). 



impressions are distinguished from those of Lepidodendrids by longi- 

 tudinal ribbings or flutings, ornamented with seal-like impressions 

 (sigilla, a seal), in vertical rows (Figs. 499-502). Little is known of 

 their leaves, though they seem to have been similar to those of Lepido- 

 dendron (Fig. 503). 



The best general conception which we can form of the Sigillaria 

 would represent it as a tall, gently-tapering trunk, longitudinally fluted 



