ON THE EXPERIMENTAL HYBRIDIZATION OF ECHINOIDS. 287  
1. E ^ X B(f  
>r  
)0  
12  
13 W // \\ I 11 15  
17  
18  
19 I I 20  
21  
2 2 II // ^'2>  
-A  
27  
2t  
28 \\ 29  
25  
31  
II 32 1 // 33 n 3^ \1 35 \  
30  
36 \/ 37 !/ 38 Ml 39 M 4-0 I  
Text-fig. 1. â€” 40 camera drawings of the apical ends of the larval skeleton of E. esculcnhns.  
