DELES8EBIA< I 101 



often reflects prismatic colours ; and the nerves are much 

 iiktc clearly defined than in N. G-melini. 



17;*. laceratum (The torn Nitophgllum) ; frond sessile or 

 Bhortli Btipitate, much branched dichotomously, traversed 

 bj numerous branching and anastomosing nerves ; segments 

 linear, variously clefl and Lobed, waved at the margin, ob- 

 tuse; Bpots of tetraspores oblong, either marginal or borne 

 on distinct leafy processes of the margin, Qrev. Alg. Brit. 

 S3. (Atlas, PL XXXIX Fig. 177.) 



Crvptopleura lacerata, A7-. Aglaiophyllum laceratum, Muni. 

 Delesseria lacerata, Ag. Wbrmskioldia lacera, Spreng. 

 Ghondrus laceratus, hyngb. Fucus Laceratus, Qmel. V. 

 crispatus, Huds. V. endivisfolius, Lightf. 



JIab. On rocks and on the stems of Lcminaria digitata, near 

 low-water mark and at a greater depth. Annual. Summer. 



This is the most generally dispersed species of NitO' 

 phyllum, and the one most usually met with within tide- 

 marks. It frequently is found fringing the steep and 



shaded sides of dee]) rocky pools, when protected from the 



sun by overhanging Fuci; lmt its favourite place of 

 growth seems to be on the stems of the larger oar-weeds. 

 The frond varies much in breadth in different specimens. 

 which however by no means represents the extreme forms. 

 Some specimens are so broad and so little divided that 

 they closely approach N. Ghnelini in aspect, especially 

 when dried; but the substance and colour ^^ the two 

 plants are essentially different, and when seen growing it 

 is impossible to mistake one I'^r the other. A very singular 

 variety of N. laceratum is frequently seen between tide- 

 marks, attaching itself by hooked Lobes to neighbouring 

 small Algae, and sometimes so intricately interwoven with 

 their stems that it cannot be extricated withoul tearing. 

 In this the frond is very narrow, o( a brighter colour 



than usual, and almost every lobe converted into a Btrong 

 recurved hook. 



171. versicolor (The changeable Nitophyllum) j stem cartila- 

 ginous, elongated, Bimple or branched, suddenly expanding 

 into a broadly Can-shaped, variously cleft frond, of a bhickish- 

 membranaceou8, highly reticulate Bubstance ami rose-red 

 colour, becoming golden-orange in fresh water; the - _- 

 incuts rounded j the apices generally thickened, and ciliiie- 

 rous : fructification unknown, ll'irr. Manual) p. 69, ( \ 

 PL XL. Fig. L81.) 



