Explanation of PI. I. 



Fig 1. Sjtonijilla lacustris encrusting stone L. Eiwa, July 1915. X§ 

 „ with vertical branches L. Eiwa July 1915. x^ 



„ catching living Yioipara sclateri. L. Biwa, July 1915. X'f 



SjidngUla semispomjiâa growing on stones. L. Biwa, Sept. 1915. X'i 



Spongilla dementis. Phase I, a thin film on a wooden pillar. L. Biwa, 



Oct. 1915. X! 

 Fig 6. Same. Phase IT, a more massive growth on the same. L. Biwa, 



Oct. 1915. Xf 

 Fig. 7. Same. Phase III, a spherical growth on the shell of living Xodularia 



reiniana. L. Eiwa, Oct. 1915. x§ 

 Fig. 8. Same. A vertical section showing abrupt change in skeletal structure. 



Dec. 1914. xi 

 Fig. 9. Sjiimi/illa fraailis covering an old bamboo stick. Oct. 1914. Xf 

 Fig. 10. S. lacustris and S. fratfilis growing together on the stem of reeds. Small 



lake at Komatsu, Nov. 1915. x^ 



