DEVELOPMENT OF CUCUMARIA ECHINATA. 



387 



be noted about the shape of the tentacles. Of the ten tentacles, the 

 ventral pair belonging to the midventral radial canal assume a quite 

 different shape from the other eight. While the latter branch regularly 

 in the same manner as in the adult, 1 the ventral pair remain for a 

 considerable time destitute of side branches and only with bifurcate 

 tips. In the adult they differ from the remaining eight in the remarka- 

 bly large size of the first branch as compared with the quite small 

 main stem, giving the appearance of the tentacles being divided at 

 this point into two branches of equal length. 



Biological Laboratory, 



Fifth High School, Kumamoto. 



May 5, 1 9 1 7. 



I) II. Ohsjiima, Zool. Mag, (Japanese), 1914. 



