lagiuous and thickened like the stem, but are either two-edged or winged, 

 and are regularly pinnate-branched throughout. The pin nee are strictly op- 

 posite, leaf-like, midribbed, lanceolate or linear-oblong, and emit from their 

 midrib 1, 2, 3, or 4 successive series of similar leaflets, each series spring- 

 ing in opposite pairs from the midrib of the preceding. The midrib in the 

 older leaflets is opaque ; in the younger it is articulate, each joint consisting 

 of 3 cells, the middle cell narrow and cylindrical, the lateral broader and 

 polygonal ; the memhram of the leaf is very delicate and thin, formed of a 

 single row of tabulated cells. ConceptacUs unknown. Tetraspores in small 

 sori, lodged in minute spore-leaves {sporopliylli) borne on the midribs of 

 the smaller leaflets. Colour a vivid pinky-red. Substance (except of the 

 main stem) soft, soon decomposing in fresh- water, and closely adhering to 

 paper in drying. 



A very fine species, whicli it would require a folio plate to 

 represent in all its beauty and size. Our octavo only suffices to 

 show the botanical characters, and a single branch. When grow- 

 ing in the water, the general frond is quite like a beautiful 

 roseate tree, with broad lanceolate leaves. The two varieties in- 

 dicated above are very strongly marked, differing from each other 

 nearly as much as D. hjpoglossum differs from B. ruscifolia, and 

 had they come from widely separated localities, I might perhaps 

 have regarded them as distinct species. But at Fremantle both 

 are found together under the same circumstances. One of them 

 {pblongifolia) is generally fertile, producing tetraspores ; the other 

 ila/icifolia) always, so far as I know, barren ; and if it be ever 

 fertile, it may possibly produce conceptacles. If this be so, the 

 differences between them would be similar to what are often 

 observed between tetraspore-bearing and conceptacle-bearing 

 individuals of the same species, the former being, almost invari- 

 ably, broader-fronded and more luxmiant than the latter. 



li'ig. 1. Delesseria dendroides, portion of the stem and one of the branches, 

 — the natural size. 2. A small leaflet of var. ^ {pblongifolia), bearing spoi-o- 

 phylli on its midrib. 3. A similar leaflet of var. a {lancifoUa), bearing 

 barren leaflets : — the latter figures magnified. 



