ROOM I. 



SIGILLARIA, 



33 



FERN-STEMS (Caulopteris). Case D. Flattened stems, 

 marked with discoidal, oblong, or ovate scars, arranged longi- 

 tudinally ; these are in all probability the trunks of the 

 arborescent ferns whose foliage abounds in the carboniferous 

 deposits. 



SIGILLARIA. Case C. Upper Shelves. Among the most 

 common and striking objects that arrest the attention of a 

 person who visits a coal-mine for the first time, and examines 

 the fossil vegetable remains which lie profusely scattered 

 among the heaps of shale, are long, flat, narrow slabs, with a 

 black glossy surface, fluted longitudinally, and uniformly 

 pitted with deep symmetrical imprints, disposed with great 



LlGX. 8. SlGTLLARIA SAULLII. COAL DEPOSITS. A PORTION OF A FLATTEHED 



STEM. 



a. External surface marked by the scars of the petioles. 



b. The inner surface exposed by the removal of the bark. 



regularity between the grooves. There are many fine speci- 

 mens on the upper shelf in Case 0. These slabs are commonly 

 from half-an-inch to an inch in thickness, and have similar 

 markings on both sides. They are the flattened trunks of 

 large trees covered by the bark in the state of coal, the 

 markings on the surface being the scars left by the separation 

 of the leaf-stalks, like the cicatrices on the stems of arborescent 

 ferns. The name Sigillaria has been given to these trees from 



D 



