(70) 



smaller proliferous branches arising here and there among the rest, 

 all the lower branches erect, upper erecto-patent ; axils, lower acute, 

 upper more wide and rounded. Structure cellular, cells oblong, those 

 composing the midrib arranged in longitudinal linear series, those of 

 the margins in linear oblique series, pointing upwards. Fructification : 

 roundish ovate spores, mostly collected in oblong sori, which are 

 aiTanged in longitudinally linear series along each side of the midrib, 

 with sometimes " scattered single spores (1) of larger size than the 

 former, dispersed over the frond." Substance membranaceous, rather 

 firm, and scarcely adhering to the paper in drying. Colour, a brownish 

 olive-green. Said, when fresh, to exhale a very disagreeable odour. 



This curious plant differs widely in its structure from every other 

 British species, and seems to have found its northern limit on our 

 southern shores. In the more southern parts of Europe, it is said to 

 be abundant, and has been found widely distributed in the tropics. We 

 have seen specimens with small dark-coloiu-ed dots scattered over the 

 surface, but could not detect anything like spores in them, and are 

 unacquainted with the "scattered capsules" mentioned by most authors. 

 The margins of the frond are normally entire, but eventually become 

 torn by the action of the waves, in the same manner as those of Alaria 

 and some other Algsc. Professor Harvey also observes {Pliyc. Brit.) 

 that Mrs. Griffiths has found fronds with the place of the frvictification 

 occupied by transparent spaces bounded by pale lines, which he sup- 

 poses may indicate a diseased state of the fruit-bearing cells. 



EXPLANATION OF PLATE CLV. 



Fig. 1. — Haliseris polypodioides, natural size. 

 2. — Surface cells with sorus. 

 3. — The same with single spores ? 

 4. — Spores from a sorus. All magnified. 



