An Annotated List of Plankton Microrganisms of the 



Japanese Coast. 



by 



K. Okamura, RirjahuhakitsM. 

 (With Plates III— VI). 



The following list of plankton microrganisms was drawn up chiefly 

 from the material collected by Mr. Shiibara along the coast of Prov. Tosa 

 in Shikoku during Sept.-Oct. in 1904 and also by myself on the coast of 

 Prov. Böshyü near the entrance to the Gulf of Tokyo in May 1906. As 

 may be expected, the material comprise a large number of those forms 

 that occur in the warm Black Current or the " Kuroshiwo." 



In the plates I have given figures of all the enlisted species, to 

 illustrate on the one hand what I have observed and on the other hand to 

 aid the students in the work of identification. The process seems to me 

 recommendable in view of the difficulty experienced by the workers in 

 this part of the world in getting access to the literature bearing on the 

 subject. The references I have given under each species in the list are 

 only those I have been able to take into consultation. 



I. Cyatiophycete. 



I. Trichodesmium erythrœum Ehrb. (Pl. VI., fig. 45). 



Gomont, 1893, p. 216; Pl. V, figs. 27-30. — Wille, 1903, p. 16; 

 fig. 11. 



Mr. Shiibara writes me that he had found this plant in great abun- 

 dance on Aug. 1 6th, 1906, at a place eighteen miles off the coast of Susaki 

 in Tosa, so that the sea presented a dark reddish colour on account of its 

 presence. He adds that he had seen no fish in the discoloured water. 



The filaments (fig. 45^-) measure 0.0075 mm. in thickness. 

 Loc. in Japan : Prov. Tosa (Aug. 16th, 1906). 



