50 W. W. WATTS. 



Robert Brown's original description of this fern (ioc. cit.) 

 was as follows: — 



"frondibus bipinnatis glabris, pinnulis linearibus margin e 

 reflexis." 

 This description, slight though it be, accurately enough 

 covers the external characters of the fronds ; and the 

 specific name pteroides, marks the Pteris-\ike appearance 

 of the pinnules. But, as pointed out by Kuhn (loc. cit.), 

 the distinguished author was in error in assigning the plant 

 to the genus Aerostichum. The mistake was easily made, 

 seeing that the sporangia, when ripe, apparently cover 

 the whole of the under side of the pinnules; but while, in 

 Aerostichum, the sporangia arise from the parenchyma 

 lying between the nerves, in Brown's plant they spring 

 from the nerves themselves. 



Desvaux 1 assigned the plant to his genus, Phorolobus, 

 a genus related to Pteris, but not recognised in Christensen's 

 44 Index Filicum." Hooker 2 kept it in Aerostichum (§Lepto- 

 chilusf). Hooker and Baker, 3 say, of Brown's plant, 

 "Aerostichum pteroides R. Br., from tropical Australia, 

 has an ebeneous naked stem 1' long, and distant lomarioid 

 fertile pinnae, the lower ones again sparingly pinnate, but 

 the barren frond is not known." There is a brief reference, 

 later in the "Synopsis," 4 to Kuhn's new genus, Neurosoria, 

 4t as having the sori confined to the nerves," but no opinion 

 is expressed regarding the validity of the genus. Moore 5 

 conjectured that the plant in question belonged either to 

 Gymnopteris or Cheilanthes. 



Kuhn (loc. cit.) reviews these facts, and adds that 

 Mettenius wrote, "in his Mss.," 



"Vidi specimen fertile in herb. Desvauxii. Sori in decursu 

 nervorum evoluti, nee parenchyma nervis interjectum intrantes 



1 Prodrome, p. 291 (1827). 2 Species Fil. V, p. 279. 



3 Synopsis Fil., p. 424. * Ibid., p. 524. s Index Fil., p. 13 (1857). 



