(112) 



oblong, clavate, an-anged in rather lax filiform series, dichotomously 

 branched and anastomosing ; giving out at their joints short, dichoto- 

 mous filaments, forming the j^eriphery, and formed towards the base of 

 more or less obconical cells, upwards of roundish moniliform cells, those 

 at the apex tufted, simple, clavate, all imbedded in a lax, very abundant 

 gelatine, which closely adheres to the paper in drying. Colour, a fine 

 transparent brownish olive, opaque, brownish when chy. Fructification : 

 obovate spores, sessile at the base of the tufted filaments of the periphery, 

 generally abundant. 



This fine species is very generally distributed, and in some places is 

 extremely abundant. On the shores of the Moray Frith, in the months 

 of July and August, it may be gathered in any quantity, and may fre- 

 quently be met with in the deeper pools near low-water mark, growing 

 parasitically on the other Algae, as well as on rocks and stones, but is 

 generally thrown up from deep water. Sometimes we have seen this 

 and the beautiful Polysifphonia hyssoides, forming almost the only rejecta- 

 menta on the beach. Yet it seems by no means general on the east 

 coast, as we have not met with it or heard of its occurrence on the coasts 

 of Forfar or Kincardineshire. It seems to delight in large, sheltered 

 bays or friths, its soft delicate fronds being but ill-suited to withstand 

 the rough and boisterous seas on the more exposed parts of the coast. 

 It is a difficult subject to dry, adhering so readily and tenaciously to the 

 paper, that it is no easy matter to prevent it adhering to the sheets as 

 well as to the paper on which it is spread. It is most easily managed 

 without pressure at all, but in that case the fronds contract very much, 

 and do not look so well. When left on the beach by the receding tide, 

 it soon dries in the sun and adheres so tenaciously to the sand or gravel, 

 that from these particles it is difficult afterwards to disengage it, even 

 by washing in water. 



EXPLANATION OF TLATE CLXVIII. 



Fig. 1. — Mesogloia vermicular is, natural size. 

 2. — Filaments of the axis and periphery. 

 3. — Filaments of the periphery, separate. 

 4. — Spores. All magnified. 



