184 THE BOTANICAL MAGAZINE. [Vol. xxxi. No. 367. 



In my specimens, thickness of blade measures 25-30 fj. in 

 the lower, and 20-22 fi in the upper part ; height of cells, 10 

 H, and nearly constant. The measurement given by Hauck 

 on the thickness of blade as 16-18 ju is certainly of a thinner 

 specimen. The figures after Bornet, reproduced in his work, 

 I.e., show the blade as thick as 21-36 p.. I have examined 

 some reliable European specimens and measured the thickness 

 varying from 22 p to 30 p. 



A specimen under Ulva Lactuca, reported by Martens to 

 have been collected in Japan, now kept in the Botanical 

 Museum of Berlin, appears to me to be referrable to this 

 species. 



Locality. Shimoda(!); Nagasaki (Martens). 



Distribution. Baltic Sea; North Sea coasts; Great Britain; 

 France. 



Monostroma zostericolum Tilden. 



Amer. Alg., No. 388. 

 = Monostroma lepidodermum Collins (non Kjellm.): Ulvac. N. 

 Amer., 15, PI. 41, fig. 10-11.— Id.: Green Alg. N. Amer., p. 213.— 

 Id.: Mar. Alg. Vancouver Isl., p. 103. — Coll., Hold, et Setch.: 

 Phyc. Bor.-Amer., No. 1272.— Setch. et Gardn.: Alg. N. W. 

 Amer., p. 209. 



This species has been synonymized by Collins under M. 

 lepidodermum Kjellm. in his Ulvaceae of N. America, I.e., in 

 1903. In 1901, I have myself collected numerous specimens 

 of it at Port San Juan with Miss Tilden who authorized 

 them to be her species. A few years later, I have collected 

 exactly similar plant in the Kuriles and on the coasts of 

 Hokkaido. In northern Kuriles I found it growing on stems 

 of Fucus evanescens, but in other localities always on leaves 

 of Zostera. Repeated examinations on the living and dried 

 specimens and referring to Kjellman's description on M. 

 lepidodermum, I have had no less hesitation to adopt Collins' 

 amalgamation of the two species and left the doubt unsolved 



