256 
Dr, Jomiso'i^* s further observations , &c. 
EXPLANATION OF PLATE XVI. 
Fig. 1 and 2. P. cornuta (front view magnified) with an 
additional head, as seen when at rest and in motion. 
Fig. 3. P.Jelina with an additional head and body, (pro- 
bably the same species as the above. ) 
Fig. 4. A separated fragment from fig. 2, now become a 
perfect animal ; the lighter portion shows the part recently 
renewed. 
5. Another fragment from the same animal, in its progress 
towards acquiring a new head. 
Fig. 6, 7, 8. Spontaneous divisions of the P. cornuta. 
Fig. 9. P. nigra, front view ; natural size. 
Fig. 10. Ditto, back view, magnified ; with the trumpet- 
shaped proboscis extended as in search of food. 
Fig. 11. Ditto, front view magnified ; showing a renewed 
anterior extremity, with a circular range of black specks or 
dots, supposed to be the eyes. 
