42 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. I. 



fossils ; the branches and twigs are generally covered with 

 foliage. 1 



Lepidostrobus. Case D. The seed-vessels are cylindrical 

 cones composed of winged scales, their axis being tra- 

 versed by a longitudinal cavity or receptacle, and terminating 

 in rhomboidal disks, imbricated from above downwards. 

 They occur of various sizes from two to six inches long, 

 and one or two inches in circumference. These fruits, like 

 the fronds of ferns, often form the nuclei of the ironstone 

 nodules so abundant in the carbonaceous clays, and are fre- 

 quently mineralized by brilliant pyrites, and galena or sulphuret 

 of lead. There is a beautiful suite of these fossils (the greater 

 part from the Author's collection) in Case D : they were 

 obtained from Coalbrook Dale. When imbedded in the rock, 

 the cones are often fringed with linear-lanceolate bractese. 



Notwithstanding the great disparity in size between the 

 existing family of club-mosses or Lycopodiacese, most of which 

 trail on the ground, and none exceed three or four feet in 

 height, and the Lepidodendra, M. Brongniart, Dr. Joseph 

 Hooker, and other eminent botanists, concur in regarding these 

 gigantic trees of the coal flora as belonging to the same tribe, 

 and only generically distinct. 2 



The visitor's attention should be directed to the beautiful 

 specimens of Lepidodendron selaginoides on coal-shale, on the 

 upper shelf of Case D ; and of L. punctatum. 



Ulodendron, Boihrodendron, ffalonia, Megaphyton. Case 

 E. The specimens to which these names are attached, are the 

 stems of plants belonging to the same family as the Lepidoden- 

 dra, but supposed to be generically, or sub-generically, distinct. 

 The Bothrodendron (pitted-stem) is remarkable for two vertical 

 rows of deep oval depressions, on opposite sides of the stem, 

 which more resemble the attachment of the bases of cones, 

 than of leaves. In Megaphyton the stem is not furrowed, the 

 leaf-scars are very large and of a horse-shoe form, and dis- 

 posed in two vertical rows on each side. 3 



1 Figured in "Medals of Creation," pp. 146, 149 ; " Wonders of Geo- 

 logy," p. 718; "Pictorial Atlas," PI. I. III. IX. XXVI. XXVII. XXXIII. 



2 The botanical reader interested in .the subject is referred to " Me- 

 moirs of the Geological Survey of Great Britain," vol. ii. ; and "Diet. 

 Univ. d' Hist. Nat.," Article, " Tableau des Genres de Vggetaux Fos- 

 siles," Paris, 1849. 



3 "Pictorial Atlas," PL XXV. 



