AUSTBALIAN FEBNS 47 



to think that some of the so called species cannot be retained. 

 When growing near the water and in the shade, G. micropJiylla, 

 looks green and fresh, but as the observer ascends the rocky 

 banks, the same fern becomes more coriaceous and diminutive, 

 whilst the under surface of the frond assumes a white or glaucous 

 appearance. The same may be said of G. flabellata ; but Dr. 

 F. Mueller differs from the opinion that this species gradually 

 passes into G. Hermanni, as the latter is somewhat rigid, the 

 capsules are more numerous than in the preceding species, and 

 the under surface of the frond is glaucous. Dr. Mueller reports 

 that G. dicarpa, has lately been found at Rockingham Bay. 



SUB-ORDER 2. Polyp odiacecs. 



This is a much larger division than the preceding, and is char- 

 acterised by dorsal sori, placed generally near the margin, various 

 in form, and sometimes constituting a uniform linear or spread- 

 ing mass, either naked or furnished with an indusium. The cap- 

 sules are one-celled, with a longitudinal or oblique elastic ring. 

 The genera to be considered in this suborder are AlsopJiila, DicJc- 

 sonia, HymenopJiyllum, and Tricliomanes> and they comprise species 

 of very variable size, some being minute ferns of a moss-like ap- 

 pearance, whilst others are gigantic tree-ferns rising to the height 

 of fifty or sixty feet. The genus AlsopJiila was probably so 

 named by Brown, because many of the species abound principally 

 in shady and sheltered woods (from alsos, a wood and phileo, to 

 love), and it comprises some of our noblest tree-ferns. The sori 

 are of a globular form, and strictly speaking, they have no indu- 

 sium, whilst the veins are pinnated more or less forked. The 

 only species of AlsopJiila from this country, described by Sir "W. 

 Hooker, is A. Australia, but since the publication of the first vol- 

 ume of the " Species Eilicum," other species have been dis- 

 covered, so that in all probability we have five or six well-defined 

 species. A. Australia is mentioned as " probably a rare species," 

 but this is not altogether correct, for it has a very wide range in 

 Australia, being found in moist and shady places nearly all along 

 the eastern coast. This species is still found in the neighbour- 

 hood of Sydney, but it is diminutive when compared with tree- 

 ferns of the same kind growing on the Blue Mountains, and in 

 Gipps Land. It has bipiunate fronds, pinnules linear-lanceolate, 

 acuminate, paler or glaucous beneath, and the rachis is of a light- 



