AUSTRALIAN FERNS. 45 



he distributed the species, so far as they have been ascer- 

 tained, under the following sub-orders, viz., : (1.) GleicJieniacecB ; 

 (2.) Polypodiacea ; (3.) Davalliece ; (4.) Pteride a ; (5.) Lo- 

 mariece ; (6.) Aspleniece ; (7.) Scolopendriece ; (8.) Aspidiacece ; 

 (9.) PolypodiecE ; (10.) Osmundacece, ; and (11.) Ophioglossece. 

 With the exception of one sub-order (Scolopendriece) , which does 

 not appear to be represented by any species in this part of the 

 world, our Australian genera of ferns may be conveniently ar- 

 ranged under the sub-orders enumerated, whilst many additions 

 may be made to the species from the discoveries of recent ex- 

 plorers, the most remarkable of which have lately been noticpd 

 by the indefatigable Dr. F. Mueller, in his excellent " Fragmenta 

 PhytographiaD Australia." 



SUB-ORDER 1. Gleicheniacece. 



In this sub-order the fructification consists of sori, nearly 

 globular in form either concealed by the revolute margins of the 

 fronds, or lying on the under surface without any indusium. 

 The two genera, Platyzoma and Glewhenia, are retained by Sir 

 "W. Hooker, as well as by Endlicher, but as the former suggests 

 the propriety of uniting them, Dr. F. Mueller, in his work on the 

 Vegetation of the Chatham Islands, reduces Brown's P. micro- 

 pJiyllum to G. Platyzoma. According to this view, therefore, 

 the sub-order will contain only one genus, of which there are 

 four species in Australia, viz., G. Platyzoma, G. microphylla, (of 

 which G. rupestris, and G.speluncoe, are to be regarded as varieties), 

 G. flabellata and G. Hermcmni, (Veg. Chatham Is., p. 63.) 

 Platyzoma is found in Queensland, and in tropical New Holland, 

 and differs from the others in having simple unbranched fronds. 

 The sori are very few, and concealed by the margins of the pinna?, 

 whilst the roots are creeping and throw up a number of crowded, 

 erect, linear fronds. The so-called species Gleichenia speluncce 

 and G. rupestris are common in the neighbourhood of Sydney and 

 other parts of NCAV South Wales, but as they seem to pass into 

 each other, and finally to attain their complete development in 

 G. microphylla, it seems reasonable to regard them as mere varieties 

 of that species. If we were to form our opinion from dried speci- 

 mens without any reference to the living plants, we might feel 

 disposed to retain many species of this genus which are now 

 united ; but, on the other hand, if we take into consideration the 



