504 SUBANTARCTIC ISLANDS OF NEW ZEALAND. [Marine Algae. 



Now, the most careful and elaborate discussion of any of the species of Porphyra 

 yet put forth is that of H. T. Hus.( i) Under the direction of Professor W. T. Setchell, 

 he has described the forms of Porphyra of the north-west Pacific coast. Taking 

 advantage of the kind offer of Professor Setchell, I forwarded to him specimens of 

 one of the common forms of Pofphyra from our coast. He defined it as P. 'perforata, 

 f. lanceolata, Setchell and Hus, and stated, " The specimens agree perfectly with a 

 form on our Californian coast which we call P. perforata, f. lanceolata. It is probably 

 only a subspecies of P. umbilicalis (P. laciniata, P. vulgaris, &c,), the common, and 

 as I believe thoroughly cosmopolitan, species." We are thus apparently left with 

 three species of Porphyra in New Zealand waters — P. nobilis, J. Ag. ; P. perforata, 

 J. Ag. ; and P. columbina, Mont. The first and third of these species will be found 

 marked as " common " in my revised list of New Zealand seaweeds. I now consider 

 that I was at least premature in identifying certain forms of Porphyra on the New 

 Zealand coast as P. nohilis{-). I had examined them, and found them to be mono- 

 stromatic, and otherwise agreeing with Agardh's description of P. nobilis. A fuller 

 investigation of them has shown me that some at least of those I thought to be mono- 

 stromatic are monostromatic only at the edges of the frond and in the younger por- 

 tions, and in identifying these with Agardh's P. nobilis I was doubtless in error. 

 (It may perhaps be mentioned here that a very distinct and still undescribed species 

 of Porphyra is to be found in most parts of New Zealand, growing on Durvillaea 

 antarctica.) 



Specimens of Porphyra were collected both by Mr. Crosby Smith and myself 

 during the " Hinemoa " expedition. Those collected by myself at the Snares and at 

 Campbell Island have been identified by Mr. A. Gepp as Porphyra perforata, J. Ag., 

 and he gives as synonyms P. capensis. Hook. f. & Harv., and P. Kunthiana, Rahenh. 

 As I have already stated, I believe P. capensis, Kiitzing, is a distinct species. 

 P. Kunthiana, Kiitz., is a form from Valparaiso of which I know nothing, but which 

 Agardh thinks may possibly be identical with P. perforata. 



Porphyra nobilis, J. Agardh. 



Porphyra nobilis, J. Ag., Till. Alg. Syst. (vol. iii), vi, p. 62, 1882. 



Campbell Island ; J. C. S. Antipodes ; Dr. Cockayne ! (New Zealand, St. 

 Paul Island ?) 



Amongst the specimens collected at Perseverance Harbour, Campbell Island, 

 by Mr. Crosby Smith are some that I think must be referred to this species. The 

 mature plants are 35-40 cm. in length, broadly elliptical in outline, and from dull 

 lilac to purple in colour. They are monostromatic, and the tetrads are separated 

 from each other by a broad hyaline margin, exceeding in breadth the endochrome 

 itself. The conspicuous cell-walls mentioned by Agardh I have not seen ; but this 

 is a point on which little stress can be laid, as it depends largely upon the method 

 of preparation of the slide. The microscopic appearance of the cells on the surface 

 of the frond closely resembles that of the plant shown in tab. ii, 49, / (Agardh, loc. 

 cit.) ; and the plant agrees well in other respects with Agardh's description. 



(^) " An Account of the Species of Porphyra found on tlie Pacific Coast of Nortli America." Cali- 

 fornia Academy of Science, Botany, vol. ii, No. 6, 1902. 

 (2) Trans. KZ. Inst., vol. xxxii, p. 61. 



