PTERIDOPHYTA. 



1509 



Bowenia. The Alethopteridece are multi-pinnate ferns with a strong 

 general resemblance to the existing Pteris, and at least some of 

 which have a similar marginal fructification. The leaflets are 

 attached by their whole base, the bases of adjacent leaflets being 

 united ; and the midrib is complete. Akthopteris, of the Carbon- 

 iferous and Permian, is common to Europe and the United 

 States ; the Mesozoic forms described under this name having 

 been noticed under the head of Asplenium. Lonchopteris, of the 

 Carboniferous, is distinguished by its net venation ; while we 

 have another type in the Permian Callipteris. Another multi- 

 pinnate type is constituted by the Pecopteridece, which agree with 

 the last family in the attachment of the leaflets, with the ex- 

 ception that the adjacent bases are usually distinct ; the midrib, 

 although slender, continues to the extremity ; and the veins arise 

 less obliquely than in the Neuropteridece. The typical Pecoptei'is 



A pinna of Cteno/>te?-is cycadea ; from the Lower Lias. The right-hand figure 

 shows an enlarged pinnule or leaflet. 



contains a very large number of species, some of which are tree-like, 

 from the Devonian and Carboniferous of both Europe and North 

 America ; and many of which have been referred to the Marattiacece 

 under the names of Asterotheca, Stichopteris, &c, but which Mr 

 Kidston considers to be generically inseparable. It also occurs in 

 the Trias of Europe, and in Lower Mesozoic beds in New Zealand. 

 Other Carboniferous genera are Mariopteris, Callipteridium, and 

 Dactylotheca. In the Mesozoic we have also a large number of 



