THE ORIGLN OF PLANT LIFE ON THE LAND. 93 



refers to the genus SphenophyUum, which is closely allied to 

 Annularia (Fig. 84, «), and also a plant wnich he terms 

 Protostigma (Fig. 84, b), and believes to be the stem of a 

 tree allied to the club-mosses.^ He also finds minute branch- 

 ing stems, which he refers to the genus Psilophytou^ to be 

 mentioned in the sequel ; but as to these I have some doubts 

 whether they may not be Zoophytes, allied to the Graptolites, 

 rather than plants of that genus. Almost simultaneously with 

 these discoveries, Saporta has announced the existence of a 

 fern (Eopteris) in Silurian slates of about the same age in the 



Fig. Z^.—Eopteris MoHerei (Saporta). A Lower Silurian Fern, from France. 



South of France (Fig. 85). • This leaf presents some remarkable 

 irregularities in the forms of its pinnae, which suggest doubts as 

 to its real nature ; but if a fern, its nearest allies are certain 

 large and peculiar ferns of the Middle Devonian, which I have 

 named Megalopteris. These discoveries tend to show the 

 existence in the Lower Silurian of plants representing all the 

 three leading families of the higher cryptogams 01; flowerless 

 plants, namely, the Club-mosses, the Mare's-tails, and the Ferns. 



^ Lycopodiacece. 



