XVIII] 



LARVA 



405 



FIG. 199. 



FIG. 200. 



IG. 199. Side view of the anterior end of a larva of Ascidia which has been 

 free-swimming for two days x 375. FIG. 200. Dorsal view of the same. 

 After Kowalewsky. 



Mouth. 2. The connection of the brain with the stomodaeum. 



3. Endostyle. 4. Intestine. 5. Branchial cavity. 6. 1st gill-slit. 

 7. 2nd gill-slit. 8. Atrial opening. 9. Blood corpuscles. 10. Cavity 

 of brain. 11. Dorsal nerve-tube. 12. Notochord. 13. Muscles. 

 14. Fixing orgcans. 15. Otolith. _16. Eye. 



