174 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 30 Ser. 



to be a step in the right direction, since, as Rosenvinge 

 points out, the distromatic species are frequently monostro- 

 matic in portions of the frond. The writer has often found 

 specimens of P. iiiiniata, P. tenuissima and P. ahyssicola 

 which were partly monostromatic, partly distromatic in the 

 purely vegetative portions of the fronds. 



Even though the distromatic character is far more con- 

 stant than was originally supposed, it seems to the writer 

 there exists no sufficient reason to subdivide the genus, 

 since the plants agree so entirely in habit and external 

 characters as to be readily recognized by the collector as 

 belonging to the genus Porfhyra. 



Other contributors to our knowledge of the genus Po7-- 

 -phyra are FosHe (1890) and Stromfelt (1886), both of 

 whom chiefly investigated the waters of Northern Europe. 



The species of the genus Porphyra in Asiatic waters 

 have been little studied. Suringar (1870) mentions P. vul- 

 garis as occurring in Japan. Afterwards Kjellman (1897) 

 studied the species of Porphyra of the coast of Japan, and 

 in his paper enumerates six new Japanese species. 



One of the first to mention Porphyra in America was 

 Ruprecht (1852). In an account of a species of Phyllo- 

 sfadix collected by Wosnessenski near the mouth of the 

 stream Slavjanka (Russian River!), he refers to a para- 

 sitic species of Porfhyra, occurring on the blades; "gegen 

 die Blattenden zu, finden sich kleine parasitirende Exem- 

 plaren von Porfhyi-a.''' From the fact that P. naiaduvi 

 And. is the only species of Porphyra occurring with any 

 regularity on PJiyllospadix, it is more than probable that 

 this is the species referred to. 



Harvey (1858) in his account of American Algse, men- 

 tions but a single species, P. vulgaris, found on both the 

 east and west coast. He is inclined to unite P. vulgaris 

 Ag., P. laciniata Ag., P. purpjirea Ag., P. linearis Grev., 

 and P. amcthystea Kiitz. under the name P. vulgaris. Later, 

 Farlow (1881) described P. laciniata h.^. as a cosmopolitan 

 species, and mentions P. leucosticta Thur. as probably 

 occurring in New England, but not yet certainly observed. 



