PLATE VII. 



FIGS. 



1-4. Ascidia rudis Alder, (p. 100) 1. Test: natural size. 

 2. Mantle : natural size. 3. Part of branchial sac : 

 magnified. 4. Ocelli : highly magnified. 

 5. Ascidia venosa Mull. (p. 102) Test : natural size. 



6-8. Ascidia depressa A. & H. (p. Ill) 6. Test: natural 

 size. 7 and 8. Views of mantle : natural size (7, 

 right side ; 8, left side) . 



9-11. Ascidia aculeata Alder, (p. 114) 9. Test: natural 

 size. 10. Mantle : natural size. 11. Part of bran- 

 chial sac : magnified. 



