The Ascidian Half-Embryo. 57 



Fig. 6, A embryo. 



Fig. 7, passage to \\ embryo. 



Fig. 8, \\ embryo. 



Figs. 9-12, cleavage of the right % blastomere, from the side. 



Fig. 9, | embryo. 



Fig. 10, T 8 g embryo. 



Fig. 11, \\ embryo. 



Fig. 12, \% embryo. 



Figs. 13-16, cleavage of the right % blastomere, from the front. 



Fig. 13, f embryo. 



Fig. 14, f- embryo. 



Fig. 15, passage to r \ embryo. 



Fig. 16, complete T \ embryo. 



Explanation op Plate Y. 



Figs. 17-24, cleavage of the % blastomere, ventral view. 

 Fig. 17, f embryo. 

 Fig. 18, passage to T 4 5 . 

 Fig. 19, complete T 4 5 . 

 Fig. 20, 2 6 ¥ embryo. 



Fig. 21 , /a embryo, immediately after division. 

 Fig. 22, g 8 ^ embryo, in resting condition. 

 Fig. 23, passage to || stage. 

 Fig. 24, complete |f embryo. 



Fig. 25, 34 larva. The arrow indicates the long axis. 



Fig. 26, two }£ larvae, from same egg. The arrows indicate the principal 

 axes. 



