BOOM I. STI&MARIA. 39 



carboniferous deposits containing scores of erect trees with 

 their roots spreading into their native soil, presenting peculiar 

 facilities for verifying the observations made in England. In 

 an interesting memoir on the coal-fields of Nova Scotia, Mr. 

 Richard Brown has given a detailed account of numerous 

 examples of stems of Sigillariee, and of Lepidodendra, (a tribe 

 of gigantic club-mosses of which we shall treat in the sequel,) 

 with the roots attached ; these roots having, in every instance, 

 the character and structure of Stigmariae. The annexed 

 figure (Lign. 10) represents an erect trunk of Sigillaria 

 alternans, with roots (Stigmarise) extending into the surround- 

 ing clay. 



In another example (Lign. 11.) discovered by Mr. Brown, the 

 stem of the tree was broken off close to the roots, and the hollow 

 cylinder of bark (a,) was bent down and doubled over by the 

 pressure of the surrounding mud, so as effectually to close up 

 the aperture, and leave only a few irregular cicatrices con- 

 verging near the apex ; the structure, arrangement, and 

 number of the tap-roots, as well as the horizontal ramifications, 

 were similar to those in Lign. 10. This fossil explains the true 

 nature of the " dome-shaped" plant figured in the Fossil Flora, 

 and in Dr. Buckland's Essay. 1 



I subjoin another sketch from the same memoir in illustra- 



Roof of Shale full of leaves, &c. 



Main coal seam, 6 feet thick. 



Under Hav with Stigmariae. 



LIGN. 12. STEM OP A LEFIDODENDRON, WITH STIGMARIA-ROOTS. 

 (From Mr. Brown's Memoir.) 



tion of this subject : the stem of a Lepidodendron with roots, 

 which are Stigmarise. 



The stems and the roots of this tree were similar t 



1 See " Pictorial Atlas of Organic Remains/' pp. 198202. 



