i64 BLECHNOID FERNS [CH. 



be taken first, as probably representing a prior type phyletically. It dififers 

 from Eu-Blechniim in the relation of the sorus to the ostensible margin of 

 the leaf In Lomaria the actual margin of the narrow fertile pinna is curved 

 downwards as in Matteuccia struthiopteris (Fig. 678, E): this is the "indusium 

 marginarium" of Presl's Tentamen{\'6'>fi, p. 141). But in Blccluium {I.e. p. loi) 



Fig. 686. Ilabil ol lUcihiiniii litinilart (Tliiinbg.) Kuhn, showing tlie dendroid 

 character, with dimorphic leaves, the sporophylls being erect, the trophophylls 

 spreading: from South Brazil. (After Wacket, from Christ.) 



he speaks of an "indusium lineare, scariosum, margine libero, costam 

 respiciente": and later (p. 102) more explicitly he says: "attamen margo 

 frondis semper evidentissime liber est, et indusium proprium adest." 

 Clearly Presl held the indusia in his two distinct genera of Lomaria and 

 Blechnum to be essentially different things. But comparative study of the 



