AUSTRALIAN PEEKS. 77 



which Dr. P. Mueller reports have been collected near Rocking- 

 ham Bay. This fern is a foot or more in length, of a linear- 

 lanceolate shape, with sori immersed, and anastomosing (that is 

 causing an angular or netted formation from the union of the 

 veins), and occupying the whole of the frond. The genus Vit- 

 taria, of which one species occurs in Australia, viz., V. rigida, is 

 so called on account of the narrow ribbon-like appearance of the 

 fronds which resemble simple-leaved grass-like plants. F. elongata, 

 which is a mere variety of F. rigida, was known to Robert Brown 

 as a tropical fern, and it was also collected by the late Allan 

 Cunningham and Mr. C. Moore, on our tropical Eastern coast. 



SUB-ORDER 11. Acrostichea. 



In tljis suborder, the sori have not any involucre, are on the 

 surface, and apparently cover the whole under side of the frond, 

 or segments with a reniform stratum of capsules. The veins 

 vary considerably, and the fronds are simple or compound, fre- 

 quently of two forms. The first genus for consideration is Acros- 

 tichum, a word derived from acros and stichos, " the commencement 

 of a verse," because the reverse of the fronds indicated traces of 

 lines, resembling the beginning of lines of poetry. As this 

 character, however, does not apply to all the species, it is better 

 to regard Acrosticlium as a genus distinguished by a uniform mass 

 of sori, clothing nearly the whole under side of the fronds, and 

 having simple or compound veins uniting in various ways. A. 

 conforme, A. repandum, A. aureum, A. pteroides. and A. spicatum, 

 have been found by Dr. I\ Mueller and others, principally in 

 Tropical Australia, but A. pteroides (of which only a solitary 

 specimen was known to Sir W. Hooker) is regarded as a doubt- 

 ful species. In the next genus, Platy cerium (from platys, broad, 

 and ceras, a horn, in allusion to the shape of the frond) differs 

 from the preceding chiefly in having only a portion of the under 

 side of the frond covered with sori. The fronds are also large, 

 and of two shapes, the new annual fronds being as it were im- 

 posed upon the old withered and dead ones. P. alcicorne is 

 a very common fern in Australia, and generally grows on rocks 

 or 1 trees, being well known under the popular name " Staghorn." 

 P. grande, which occurs in the northern parts of the colony, and 

 in the north-eastern coast of Australia, has fronds sometimes five 

 or six feet long, and seems identical with the species found at 

 Singapore. 



