64 A CONTRIBUTION TO, ETC. 



for mathematical precision or for characters which can, without 

 failure, include every form in groups." Sub-order (7) Scolopen- 

 drieoe is not represented in this part of the world, and the des- 

 cribed species do not exceed eight. 



The species of this order, according to Dr. P. Mueller, are 

 arranged in the following manner : Asplenium nidus ; A. simplici- 

 frons ; A. attenuatum ; A. paleaceum ; A.falcatum; A. furcatum ; 

 A. cuneatum including A. laserpitiifolium; A. flabellifolium, with 

 a remarkable variety A. dissectum, collected by the Rev. R. L. 

 King, of Parramatta : A. tricJiomanes ; A. marinum, with the 

 varieties, obtusatwm, bulbiferum, &ndflaceidum ; A. umbrosum ; A. 

 polypodioides ; and A. sylvaticum. The second of these is a new 

 species, described in the Fragmenta, vol. 5, p. 74. This was dis- 

 covered near Buckingham Bay, associated with several species of 

 Acrosticlium, and has long, narrow, lanceolate fronds. Some beau- 

 tiful specimens of A. sylvaticum (Diplazium) were collected at 

 the Richmond River by the late Mr. Macgillivray. This is a very 

 elegant fern, with a short erect caudex, a stipes about a foot long, 

 and fronds sometimes two feet and upwards in length. It is re- 

 markable on account of its double involucre, and for the fact that 

 the same species occurs in the Mauritius, Ceylon, Malacca, Java 

 &c. A. marinum was lately found by J. R. Young, Esq., of the 

 G-lebe, in its form of obtusatum, not many miles from Sydney, 

 growing close to the salt water. It would be interesting to those 

 who wish to arrange ferns systematically, to ascertain if the 

 various forms of this species could be developed by cultivation, 

 for notwithstanding the views of Sir William Hooker and Dr. 

 F. Mueller, whose opinions are indeed entitled to the greatest 

 consideration, I am not aware that the varieties in question have 

 ever been raised from the same spores by any artificial means. 

 Until the amount of variation under cultivation can be distinctly 

 shown, it seems impossible to determine whether A.flaccidum is in- 

 deed one of the forms of the well known A. marinum. 

 SUB- ORDER 8. AspidiacecB. 



This sub-order is distinguished by dorsal sori of a roundish 

 shape, with an involucre either peltate and fixed by the centre, 

 or reniform and fixed by the sinus (that is the recess formed by 

 the lobe), whilst the veins vary considerably in the species. In 

 this group we are to consider Aspidiwm, Nephrodiwi, and 



