CHAPTER XI. 



II. SPHENOPHYLLALES. 



Sphenophyllum. 



The genus Sphenophyllum is placed in a special class, as 

 representing a type which cannot be legitimately included in 

 any of the existing groups of Vascular Cryptogams. Although 

 this Palaeozoic genus possesses points of contact with various 

 living plants, it is generally admitted by palaeobotanists that it 

 constitutes a somewhat isolated type among the Pteridophytes 

 of the Coal-Measures. Our knowledge of the anatomy of both 

 vegetative shoots and strobili is now fairly complete, and the 

 facts that we possess are in favour of excluding the genus from 

 any of the three main divisions of the Pteridophyta. 



In Scheuchzer's Herbarium Diluvianum there is a careful 

 drawing of some fragments of slender twigs, from an English 

 locality, bearing verticils of cuneiform leaves, which the author 

 compares with the common Galium^. As regards superficial 

 external resemblance, the Galium of our hedgerows agrees very 

 closely with what must have been the appearance of fresh green 

 shoots of Sphenophyllum. 



A twig of the same species of Sphenophyllum is figured by 

 Schlotheim' in the first part of his work on fossil plants ; he 

 regards it as probably a fragment of some species of Palm. 

 Sternberg^ was the first to institute a generic name for this 

 genus of plants, and specimens were described by him in 1825 



1 Scheuchzer (1723), p. 19, PI. iv. fig. 1. 



2 Schlotheim (04), PI. ii. fig. 24, p. 67. =' Sternberg (26), p. 82. 



