STIGMARIA 101 
Another plant-giant of the Carboniferous Period 
was the Sigillaria (Latin, sigillum =a seal), so called 
from the seal-like leaf-scars which the fossils show. 
The fossil stems of these plants are fluted, and each 
rib is marked with a row of leaf-scars. Some very 
large trunks have been discovered, one found at 
Saarbrticken, in Germany, being six feet in diameter 
at the base. The roots of Sigillaria are called Stig- 
Fie. 41.—Srump anp Roots or STIGMARIA FICOIDES FROM 
THE CoaL-MrasurEs, CLAYTON, YORKSHIRE. 
maria (Greek, stigma=a puncture), and get their 
name from their punctured or pitted surfaces ; they 
are commonly found in the. fire-clay which generally 
lies under coal-seams. A specimen of Stigmaria 
showing a tree-stump over four feet in diameter, 
and roots thirty feet across, was found in a sand- 
stone quarry at Clayton, Yorkshire ; it may now be 
Seen in Owens College Museum, Manchester (see 
Fig. 41). There are found in Carboniferous: rocks 
