I 



CHARACTERS OF TRIBES AND GENERA. 209 



specimens of the same species are found, some with the 

 indusia and some without, for instance, being present at 

 the distribution of Cuming's Philippine Island collection 

 of specimens in 1841, I noted that number 315 was 

 indusiate, which in my enumeration of that collection 

 I named NepJirodium simplicifolium. It was not till nearly 

 twenty years afterwards when Cuming's specimens of this 

 species came under Sir William Hooker's observation for 

 entry in the " Species Filicum," that finding it had no 

 indusium he placed it under Polypodium in the section 

 Goniopteris, 



Another example of the untrustworthiness of the indu- 

 sium as a generic character is verified in Phegopteris 

 Seemanni, described by me in the " Botany of the Voyage 

 of the Herald," from specimens collected by Seemann in 

 Darien ; Mettenius also retains it in Phegopteris, but makes 

 it a synonym of Aspidium brachyodon of Elunze, while in 

 the "Species Filicum" it is placed in Nephrodium, the 

 " involucre " being described as " small fugaceous," thus 

 showing that at least some of the specimens in the Kew 

 herbarium were indusiate ; but as several American locali- 

 ties, as also the Malayan Peninsular and islands, are given 

 as stations for this Fern, it is therefore quite possible that 

 the American and Malayan specimens represent two dis- 

 tinct species, one with indusiate sori, and the other with 

 naked. This and several other allied species is peculiar 

 in having stout arboroid stems a foot or more in height, 

 with the pinnae articulate with the rachis, as also in the 

 lobes of the pinnae being joined by a line like a seam, 

 which extends from the mid-rib of the pinnae to the sinus 

 between each two lobes, by which in time the lobes become 

 separated as if artificially cut. Setting aside the presence or 

 absence of the indusium, and in the venules being free 

 p 



