188 THE BOTANICAL MAGAZINE. [Vol. xxxi. No. so?. 



Monostroma latissimum Wittr. 



Monostroma, p. 33, Tab. I, fig. 4.— De Toni : Syll. Alg. I, p. 

 102. — Foslie: Mar. Alg. Norway, Contr. I., p. 114. — Coll., Hold. 

 et Setch. : Phyc. Bor.-Amer. No. 14, No. 1122. — Collins : Ulvaceae 

 N. Amer., p. 16.— Id. : Green Alg. N. Amer., p. 211. — Id. . Mar. 

 Alg. Vancouver Isl., p. 207. — Setch. et Gardn. : Alg. N. W. 

 Amer., p. 207. — Wittr. et Nordst. : Alg. Exsic., No. 145. 

 (For other references, see : De Toni, I.e.). 



This species seems to be fairly common in middle part of 

 the Pacific side of Japan. 



Locality. Awa Prov. (J. Nikai, Nos. 2582. 2583); Owari 

 Prov. (S. Narita, No. 14). 



Distribution. West coast of Europe.; Mediterranean Sea; 

 Atlantic coast of N. America, Main to Florida; Alaska to 

 Washington; New Zealand. 



Monostroma Vahlii J. Ag. 



Till Alg. System. VI, p. 109, fig. 84-89.— De Toni : Syll. Alg. I, 

 p. 106.— Setch. et Gardn. : Alg. N. W. Amer., p. 208. 

 = Monostroma Grevillei Wittr. /3 Vahlii Rosenv. : Gronl. Havalg- 

 er, p. 949. — Jonss. : Mar. Alg. East Greenl., p. 64. — Collins : 

 Ulvaceae N. Amer., p. 13. — Id. : Green Alg. N. Amer., p. 209. 



In the external appearance of frond my specimens are not 

 easily separable from both M. cylindraceum Kjellm. and M. 

 Vahlii J. Ag. Kjellman's plant is described as having the 

 thickness of frond 40-45 // and the height of cells 10-15 /jl. In 

 my specimens, frond is very thin measuring but about 10 /j. ; 

 cells, in cross sections, compressed rectangular, 4-5 p. in height 

 and 6-9 /J- in breadth. J. Agardh did not give any measure- 

 ment in describing his species. Had the figures 85-89 in Till 

 Alg. System., I.e., been 540 times of magnification of natural 

 size, then my specimens agree with his in every respect. I have 

 seen the original specimen at Lund and assured that my speci- 

 mens have similar appearance to it, but left the structure 



