1906.] NATURAL SCIENCES OF PHILADELPHIA. 9 



Fig. 6. Similar reconstruction from sagittal sections. Left-hand aspect. Ox-i- 

 duct and vas deferens of right side omitted. Lettering as above. Mag. 10 d. 



Fig. 7. Freehand sketch of the anterior piece of a living specimen soon after 

 fission. Mag. 5 d. 



Fig. 8. Similar drawing from a larger anterior piece several davs after fission, 

 showing considerable regeneration. 



Fig. 9. Posterior piece soon after fission, showing the two separate branches 

 of the digestive tract. Mag. 10 d. 



Fig. 10. Similar posterior piece after several days' regeneration (probably about 

 a week). Branches of digestive tract united and new pharj-nx and eyes 

 formed. Mag. 10 d. 



