52 A CO-NTRTBTJTTO^ TO, ETC. 



tained as a distinct species, though further inquiry may lead to 

 the conclusion that it is a mere variety of the preceding. L. 

 lanuginosa (see Fragmenta, vol. 4, p. 166), a species previously 

 found on trees in Singapore and Penang, as well as in New 

 G-uinea, has lately been discovered at Rockingham Bay ; and L. 

 flcibellulata, a fern common to China, Sumatra, Java, &c., occurs 

 at Port Essington. According to Hooker, many authors unite 

 this suborder with Dicksoniece, with which, indeed, it seems 

 closely allied, but until botanists can settle the many differences 

 of opinion which they entertain as to the limit of the group and 

 the genera which compose it, the present arrangement seems the 

 most convenient. 



Dr. F. Mueller considers that Dicksonia davallioides is a mere 

 variety of Davalliaflaccida. This opinion is formed from a com- 

 parison of specimens from Norfolk Island, the Blue Mountains, 

 and the Macleay, Hastings, and Clarence Bivers. It does not 

 appear that Oystopteiiffrayilis, though frequent in New Zealand, 

 and in the alpine regions of Tasmania, has yet been found in 

 Australia. In addition to the species of Lindseea already enume- 

 rated, Dr. Mueller states that he has received specimens of L. 

 Fraseri from Stadbrooke Island, Cleveland, and Moreton Bay ; 

 and of L. tricJiomanoides from Illawarra. and Bockingham Bay ; 

 but he adds that until further investigations have taken place, it 

 is impossible to determine whether some of the species can be 

 maintained. L. cultrata and L. concinna have lately been found 

 at Buckingham Bay. 



SUB-ORDER 4. Pteridece 



In this suborder are included several genera common in Aus- 

 tralia, characterised by orbicular sori, oblong or linear often con- 

 tinuous, marginal, situated at the apices of the veins with an in- 

 volucre formed of the replicate margin. This, of course, is a 

 mere general character of a most extensive group, varying very 

 much in appearance and habit, but as the genera of which it is 

 composed pass almost imperceptibly into each other, they cannot 

 be satisfactorily placed in separate sections. The genera with 

 which we are more immediately concerned in Australia are 

 Adiantum, Hypolepis, CTieilanthts, Pellcea, Pteris, and Ceratopteris. 

 In the first of these, A. Jiispidulum, A. formosum and A. assimile^ 

 are very abundant in Eastern Australia. At first sight, the last 



41 



