INTRODUCTION. VU 



still find a parallel, Tree Ferns of great size are there flour- 

 ishing, consequently it is not improbable in that far-distant 

 period, when Ferns were arborescent in England, that a much 

 warmer temperature, a more humid air, and in short a more 

 tropical climate then existed. 



It is perhaps not generally known, except to Geologists, that 

 of the Ferns found fossil, none of the species have been found 

 growing in the present age. 



Of the fossil Ferns, the following classification may be 

 briefly enumerated : — 



Pacliypteris — Two species: from the oolite formation. 

 Gydopteris — Pour species in the coal formation, one in the 



oolite, and one in the transition rocks. 

 Sijhenopteris — ]N"early forty species. 

 Olossopteris — Two species in the coal, one in the lias, and one 



in the oolite. 

 Neuropteris — Twenty-four species in the coal, three in the new 



red sandstone, one in the muschelkalk, and one in the 



anthracite of Savoy. 

 Odontopteris — Five species in the coal formation. 

 Anomopteris — One species in the new red sandstone. 

 Toeniopteris — Three species in the has and oolite. 

 Pecopteris — Sixty species in the coal, ten in the oolite, two 



in the lias, and one in the beds above the chalk. 

 Loncliopteris — Two species in the coal formation. 

 Clatliropteris — One species in the lias. 

 Schizopteris — One species in the coal measure. 

 Otopteris. 

 Caidopteris. 



Altogether enumerating about one hundred and seventy species, 

 amongst which some of the most beautiful are Pecopteris 

 adiantoides , Loncliopteris Mantelli, Tceniopteris vittata, Neurop- 

 teris Loshii, Odontopteris minor, and Sphenopteris crenata. 



In conclusion it will be necessary, in as few words as possi- 

 ble, to describe the various terms which will be used from time 

 to time in the delineation of the Ferns; and I cannot do this 

 better than adopt the excellent descriptions given in "Smith's 

 genera of Ferns:" — 



Ferns consist of fronds or leaves, which are produced from 

 a rhizoma; the fronds unfold in a spiral manner, and are 



