K. MITSÜKUBI. 



5 P. M. Tide was just advancing on the lowest limit of the 

 somewhat squarish circumscribed area. Individuals had 

 not stirred from their positions in the morning. As tide 

 arose, the individuals were gradually driven upwards. 

 Movements of the animals took place, when splashes of 

 waves receded and left them momentarily quiet. 3 indivi- 

 duals remained below submerged, but others crawled np 

 higher and higher and were driven out of the circumscribed 

 area, until the individuals were about 5 cm. above the 

 highest point of the circumscribed area. Tins was at 6: 

 '20 P. M. when I had to leave. The tide could not have 

 risen much higher and receded during the night. 

 Aug. 31 : — When I went to the spot next morning at 5 A. M., 

 tide was rising again but had not yet reached the circums- 

 cribed area. I was able to recognize 17 out of the 20 

 individuals which had originally been in the circumscribed 

 area, with one other doubtful one, distributed as follows: — 

 1 was in a crevice about 25 cm. to the left (looking from 

 seaward) of the original area, a trifle below the level 

 as when I left last night. All the rest had moved 

 down. 



4 were in the original circumscribed area. 



5 were on the same level as the original area but outside 



it, furthest one being about 10 cm. to the right. 

 1 doubtful, at the same level. 



7 were below the level of the original area, the lowest 

 having gone down about 15 cm., below the lowest 

 side of the area, at the then w T ater's edge. 



It was evident that after the tide receded, some of the molluscs 

 t down seaward. I have further notes on the same area as follows : — ■ 

 Aug. 31, 8 : 45 A. M. Nearly full tide. The tide did not rise 

 as high as the preceding evening. It affected only the 

 lowest individuals which moved up about 15 cm. 



