Plate LXXIV. 



Fig. 346. PORPHYRA VULGARIS. 



Colour. Bright purple; almost rosy when dry; very glossy. 

 Substance. Delicately membranaceous; very thin. 



Character of Frond. A flat, narrow, ribles^, leafy expansion, with a pointed end. 

 Quite simple; but the margins becoming more or less strongly waved and 

 plaited as the plant grows. 



3feasurement. From an inch to 1 or 2 feet long. Not more than 3 inches wide, 

 and young specimens mere threads. 



Fructification. Minute seeds (zoospores) formed of the colouring matter in the cells 

 i of which the frond-membrane is composed (four in each cell); and in due time 



dropping out. 



Habitat. Our coasts generally. On rocks, &c. between tide-marks; from high- water 

 mark downwards. 



It is almost " past a peradventure " that this plant is but a different condition 

 of the preceding one, Porpliyra laciniata (see last Plate). The narrowest of the 

 specimens in Fig. 346 are found in winter or early spring covering the rocks 

 near high-water mark with their tiny, purplish-pink, satiny fronds. Later in 

 the season, the larger, frilled form abounds in the same locality, as also lower 

 on the shore, where it may be found mixed with the broad divided fronds of 

 P. laciniata. All are gathered indiscriminately for the table. P. vulgaris is 

 rarely so dull coloured and greenish as P. laciniata often is; but, on the other 

 hand, P. laciniata, is .sometimes as bright as the other ever is. And intermediate 

 instances both in form and colour are met with. Dr. Harvey unites the species 

 in his Nereis Boreali- Americana, under the name laciniata. 



Fig. 347. BANGIA FUSCO-PURPTJREA. 



Colour. Blackish-purple; occasionally greenish; glossy. 

 Substance. Tenacious; soft; sticky. 



Character of Frond. Tufts of hair-like threads (^filaments)-, forming a close-clinging, 

 dark purple or greenish layer upon rocks. Filaments straight or slightly 

 curled; undivided; unbranched; tubular; containing rows of minute colour- 

 cells radiating from the centre. 



Measurement. Filaments, several inches long; their width variable; narrow ones 

 containing only one colour-cell; others from 2 up to 5; these forming (with 

 the intervals) a tesselated line across (see Figure for magnified appearance of 

 this strictly microscopic object.) 



Fructification. Minute seeds (zoospores) formed of the colour-cells in the filaments 

 (one to each cell); and in due time dropping out. 



Habitat. Our coasts generally, and in fresh-water rivers and canals. On rocks, 

 wood, &c. near high-water mark. Not uncommon. 

 73 * L 



