Ser. CHLOROSPERMEA. Fam. Ulvacee. 
Puate XCII. 
PORPHYRA LACINIATA, 4%. 
Gen. Cur. Frond delicately membranaceous, flat, purple. Fructification, 
granules, arranged in fours, scattered over the whole frond; also 
“scattered sori of oval spores.” (Ag., Grev.). Porpuyra (4y).— 
from roépupos, purple. 
Porpryra Jaciniata; frond deeply and irregularly cleft into several broad 
segments. 
PorpuyRra laciniata, 4g. Syst. p.190. dy. Ic. Alg. Eur. t. 26, 27. Grev. 
Alg. Brit. p.168. Hook. Br. Fl. vol.ii. p.310. Harv. in Mack. Fl. Fb. 
part 3. p. 241. Hare. Man. p.169. Wyatt, Alg. Danm. no. 32. Endl. 
3rd Suppl. p.19. Kitz. Phyc. Gen. p. 383. 
Porpuyra umbilicalis, Kitz. Phyc. Gen. p. 383. 
Unva laciniata, Lightf. Fl. Scot. p. 974. t.33. Roth, Fl. Germ. p. 585. Ag. 
Sp. Alg. vol. i. p. 404. 
Utva umbilicalis, #. Bot. t. 2286. Lyngb. Hyd. Dan. p. 28. 
Has. On marine rocks, within the range of the tide. Annual. Spring to 
autumn. Abundant on all our shores. 
Gzoer. Distr. Throughout the Atlantic Ocean, from the Feroe Islands to the 
Cape of Good Hope. 
Dzscr. Root, a minute disc. Fronds two to eight inches long, clustered toge- 
ther, expanded, delicately membranaceous, pellucid, very irregularly divided 
into several lobes; the point of attachment frequently within the frond, 
which is then peltate. Margin wavy, entire or irregularly cut ; apices often 
truncate. Under the microscope the whole frond appears to be divided into 
squares, in the manner of a tessellated pavement, and within each square 
are four purple granules, or spores, which constitute the fructification and 
the whole colouring matter of the frond. When not in a state of perfect 
fructification the colour is much less bright, tending to a livid olive. Besides 
the usual fructification, Dr. Greville describes a second, consisting of “ sori 
of smaller ovate granules scattered without order chiefly towards the mar- 
gins of the frond.” These I am not acquainted with. In drying, the colour 
becomes much brighter; but the glossy and delicate fronds do not adhere 
closely to paper, and shrink very much. 
This very common plant is found in most parts of the Ocean 
throughout the tropics, and exists nearly as far as vegetation 
extends towards the poles. It varies in different places, some- 
thing in substance, being thicker or thinner; something in 
colour, being sometimes of a bright purple, and sometimes much 
tinged with olivaceous green; and something in form, some indi- 
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