(42) 



middle, one to three inches long, and less than one-quarter of a line thick 

 at the base ; branches dichotomous, short, and fastigiate upwards, 

 erecto-patent, the axils mostly rounded, and rather wide, sometimes 

 acute ; the apices acute or occasionally somewhat compressed, " some- 

 times the upper branches, which have received an injury, produce dense 

 bunches of branchlets without order, but these in their divisions soon 

 assume the foz-ked character of the species." — Phyc. Brit. Structure 

 cellular, composed of two strata of cells, those in the centre oblong, 

 forming imperfectly longitudinal filaments, from which arise other 

 series at first inclined, at length vertical, moniliform and coloured, and 

 very densely packed. Substance rather firm and horny. Colour, a 

 dark brownish purple. Favellidia we have not seen in this species. 

 Nemathecia formed externally on the branches, composed of vertically 

 radiating filaments, whose articulations are at length resolved into 

 cruciate tetraspores. 



The only fructification which has been observed on this species in 

 this country, so far as we are aware, is the wart-like nemathecia which 

 arise irregularly on the surface of the branches, on which they appear 

 more like small, wart-like parasites than as bodies organically con- 

 nected with the frond. These tubercles entirely consist of densely 

 packed moniliform filaments, gradually increasing in diameter upwards ; 

 these articulations are at length entirely converted into tetraspores, 

 and when matm-e, form one of the most beautifid microscopic objects 

 imaginable. The bright pm-ple coloiu-ed granules, completely enveloped 

 in their clear, glassy pericarps, attached to each other in long, slender 

 strings, look like a collection of ruby necklaces, in settings of the 

 purest crystal. 



Imperfectly grown specimens have much the appearance of small 

 specimens of Ahnfeldtia plicata, but the minute cells of the axis of the 

 latter and much denser structure will be easily distinguished from 

 the comparatively large cells and open structure of the former. The 

 external appearance of the tubercles is also much the same in both, but 

 in those of the present species the cells are greatly larger than in those 

 of Ahnfeldtia, and their conversion into tetraspores much more perfect 

 and apparent. 



Its favourite habitat seems the somewhat sheltered sides of rocks near 

 low-water mark, or the little open pools that are often found in such 

 places, where it grows in single tufts, scattered here and there over the 

 rocks, where its slender, wiry stems may be readily passed over, as they 

 are objects of no apparent interest or beauty, especially in its more 

 usual and irregularly branched state. 



