BOT.— Vol. II.] HUS—PORPHYRA. 211 



have a cucullate base. The aureole around the disc is very 

 pronounced in this species. The frond is not plicate, but 

 on drying several folds appear in some of the older speci- 

 mens, owing to the concave nature of the frond caused by 

 the cucullate base. The margin in the older fronds is 

 much laciniate. 



The fronds are monostromatic in the vegetative part. No 

 deviation from this has been observed. The cells are 

 square with rounded angles, or may be twice as high as 

 broad or twice as broad as high. 



Sporocar-ps. — The mature frond becomes gradually 

 changed into reproductive cells of which the sporocarps 

 form the majority. They can be readily recognized by 

 their deep red color, and are sharply outlined against the 

 lighter colored antheridia. The sporocarp first divides 

 cruciately, giving rise to four cells. Each of these now 

 undergoes a parallel division, followed by a cruciate divi- 

 sion; so that in each sporocarp we finally have thirty-two 

 carpospores arranged in two tiers of sixteen each (PI. XX, 

 fig. lie; PL XXII, fig. 25). 



Antheridia. — They are found in larger or smaller, irreg- 

 ular, light-colored patches among the sporocarps. The 

 antheridium-mother-cell, by a cruciate division, gives rise 

 to four antheridia, each of which b}'^ alternating parallel 

 and cruciate divisions, as in P . perforata , give rise to 128 

 antherozoids, arranged in eight tiers of sixteen each. 



Economic Use. — This plant is largely collected by China- 

 men on the Californian coast, along with P . perforata. 

 From what could be learned, it seemed that it is much more 

 esteemed than the latter. 



Habitat. — This species is found attached to the stipes of 

 Nereocystis lutkeana in from three to five fathoms of water, 

 and is also found on rocks. After a storm it is frequently 

 found floating. 



Distribution. — Porphyra nereocystis has a very wide 

 range, having been collected at St. Paul, Kadiak Island, 

 Alaska, and as far south as San Pedro, California (57° 30'- 

 33°4o'N. lat.). 



