78 A CONTRIBUTION TO, ETC. 



The AcrosticliecB are generally of a coarser nature than other 

 ferns, and they differ from them in having the spore cases not 

 merely on the veins, but also occupying the parenchymal in- 

 terstices themselves. The thick spongy fronds of Platycerium 

 have been compared to the horns of elks, and the veins of the 

 fertile fronds run down to a stem-like base, differing from any- 

 thing in the suborder. This genus occurs frequently in New 

 South Wales, from Illawarra to the Burnett, but AcrosticJium be- 

 longs to the North and North-eastern parts of Australia. E-ock- 

 ingham Bay seems a very favourable locality for some of the 

 species. A. aiireum is widely dispersed throughout the world, 

 being found in most tropical and sub'-tropical countries, but vary- 

 ing considerably in shape. At Aneiteum, some of the pinna3 are 

 reported to be a foot and a half long, and three inches broad. 

 Brown's A. fmxinifolium is now referred to this species, as well 

 as several others formerly regarded as distinct. With regard to 

 A. pteroides, which does not appear to have come under the no- 

 tice of Dr. Mueller, the species is certainly remarkable, and it is 

 to be hoped that travellers in Tropical Australia may fall in with 

 it, as probably it may belong to another genus. 

 SUB-ORDER 12. Schizceacece. 



Having followed the arrangement of Sir W. Hooker, through 

 the preceding suborders, I now proceed to consider the Sub-orders 

 (12) Scliiz&aceGe, (13) Osmundacece, (14) Danceacece and (15) 

 Ophioglossacece, which that eminent Botanist was not permitted 

 to review. In the conclusion to the 5th vol., of the " Species 

 Filicum" he remarked that it had been his intention to include 

 Osmundacecd and OpJiioglossaccee in that volume, but that he found 

 the material too bulky, and then he adds, with becoming humility, 

 " the author is preparing, if his life and health be spared to ac- 

 complish it, a volume to be entitled " Synopsis Filicum," and to 

 add to it all needful corrections and alterations, and additional 

 species that had come into his possession during the twenty years 

 his work had been in progress." Sir William did not live to 

 complete the work he had designed, and therefore, I must now 

 turn with feelings of deep regret, to other authors for the classi- 

 fication of the remaining suborders. Before doing so, however, 

 I am sure it will not be deemed irrelevant, to pause for a moment 

 and acknowledge the services, which that distinguished botanist 



