OF THE FOSSIL PLANTS EXAMINED. 75 



GENUS V. LEPIDODENDRON. 



Stems simple or dichotomous, subcylindrical or compressed, the surface 

 covered with prominences of an elliptical form, arranged in spiral series. A 

 central axis or pith of irregular polygonal cellules, which are smaller to- 

 wards the margin. The great mass of the stem composed of uniform pa- 

 renchymatous tissue. Cylindrical processes of cellular tissue, with a central 

 fasciculus of vessels proceeding from the pith to the papillae on the surface. 



These plants resemble Lycopodium in structure and in external ap- 

 pearance. 



1. Lepidodendron Harcourtii. 

 Plates XII. and XIII. 



Coal-formation of the north of England. 



The result of my labours, as has been seen, is the description of twelve 

 species of fossil plants, viewed with reference to their organic texture. The 

 benefit which may be derived from my humble efforts may not be of great 

 importance ; but I shall enjoy the pleasure of having solicited the attention 

 of geologists to the internal structure of fossil plants generally, and of 

 having shewn the way to the accurate investigation of them. One great 

 object which I had in view, when I published my imperfect views of the 

 subject, two years ago, namely, that of directing to it " the attention of some 

 of the many eminent botanists and geologists of which our country can 

 boast," has already been in some measure accomplished ; and any assistance 

 which I can afford, I shall always be ready to accord to those who may feel 

 interested in the subject. 



