Dr. Johnson's observations on the genus planaria. 447 
9. Head and tail of P. cornuta , naturally divided. 
10. Head of P. cornuta, with tail partly renewed. 
11. Head of P. lactea, Do. Do. 
12. P. brunnea , with renewed head and tail. 
13. P. cornuta, Do. Do. 
14. Head of P. torva, highly magnified, showing the 
eyes in the centre of the white areola. 
15. P. lactea attached to a portion of a large earth- 
worm, with the abdominal tube inserted. 
16. P. cornutce preying upon an aquatic worm, showing 
at a and b the abdominal tube. 
17. Interanea of P. lactea, highly magnified, showing 
its arborescent ramifications. 
