1903.1 THREE SPECIES OE MARINE EOBALLOQYSTIS. 205 



indicating the closest relation to other allied genera. In comparing jEc6«?- 

 locystis vi'iih. C]ilorangium,^o\\\m^^ remarks: '• man kdnnte daher vielleiclit 

 Ech. als ein Clil., dessen galertstiele iramer unentwickelt bleiben, ansehen.'^ 

 The newly found species would illustrate the stages of the development, or 

 rather the retrogression in my opinion, of the stalks in a satisfactory 

 manner. Bohlin,2> again, in remarking the difference between Ecballocystis 

 and Eugelenopsis, mentions that the transverse layers in the stalks at the 

 rear of the cells are found in the latter as the cells progress forward, 

 while in the former none of such construction is to be found. In Ec, 

 Williana, however, the concentric zones are clearly visible as already 

 remarked. What I called the retrogression of the stalks above, depends 

 upon this circumstance together with the dissipation of the lower portions 

 of the branches. 



Botanical Institute, 



Imp. Univ. Tokyo. 

 Nov. 6th, 1903. 



EXPLANATION OF PLATE. 



1-15. Ecballocystis Willeana. 



1. Two thalli in habitual state ; naf. size. 



2. Longitudinal section of a thallus, moderately magnified. 



3. Yiew from the upper surface, x 285. , 



4. A peripheral portion of fig. 2. x285. 



5. Longitudinal section of a thallus with zoosporangia. x 285. 



6. Longitudinal section of a thallus near at the substratum^ to show 

 the filamentous processes of the rhizoid cells, x 285. 



7. A gelatinous branch with a number of stalks, stained with methyl- 

 green. X 285. 



8. ditto; without treating in colouring material. x285. 



9. ditto; the concentric zones of the gelatinous layers in the stalk 

 are clearly seen._^ x 285. 



10-11. Group of the peripheral cells after treating with caustic potash and 

 iodine: the pyrenoids are enveloped in the thin layers of starch, 

 stained in a dark blue colour. x 650. 



1) 1. c. p. 9. 



2) 1. c. p. 8. ; ..„.._ 



