(126) 



articulated axis of oblong cells, ultimately covered, at least in the older 

 parts, with a stratum of minute cells, interspersed with one or two 

 series of large, angular, oblong ones, the younger parts composed only 

 of the central articulated axis. Substance very flaccid, scarcely cartila- 

 ginous, rather firmly adhering to paper. Colour, a veiy dark dull 

 brownish red, almost black in the mass. Favellse terminal on short, 

 abbreviated ramuli, roundish ovate, in pairs, generally with one to four 

 short involucral ramuli, shorter than the favellae. Tetraspores on short, 

 mostly single-jointed stalks or ramuli, roundish, with a wide hyaline 

 limbus. 



The present species is certainly very closely allied to the preceding, 

 both in structure, habit, and fructification; yet we have no hesitation in 

 agreeing with Professor Harvey in keeping it distinct, believing that 

 the characters are quite sufficient to justify us in so doing. From that 

 species it may be readily distinguished by the ramuli wanting the cellular 

 covering that spreads over the main divisions of the frond ; this coating 

 is at first composed of a single stratum of cellules, through which the 

 articulated axis may be readily perceived, but as the plant advances in 

 age, the cellular coating extends iipwards, and becomes so much thick- 

 ened, that the axis cannot be seen through it, and is even sometimes 

 partially obliterated, and the stem, like that of Dasya coccinea, becomes 

 very much beset on all sides with very short, simple, articulated ramuli. 

 Its favourite habitat is under the shade of overhanging rocks, where it 

 often grows in broad patches, lying procumbent on the rock when the 

 tide has retired, or hanging in dark curtains from the projecting angles, 

 each festoon tipped with a brilliant drop of ambei'-coloured water, and 

 feeling to the touch like the realisation of the silken tassels gemmed 

 with gold and brilliants of the mermaid's halls. 



EXPLANATION OF PLATE CXL 



Fig. 1. — Ptilota elegans, natural size. 

 2. — Part of pinnule. 

 3. — Part of pinnule with tetraspores. 

 4. — Part of jiinuule with favellse. 

 5. — A tetraspore. 

 6. — Portion of stem. All mafruified. 



