102 PLANARIA. 



body thin, flattened, nearly oval, especially in earlier stages ; anterior 

 margin even ; numerous black specks, arranged irregularly towards the 

 edges of the front, and an irregular cluster behind them. Twenty of the 

 former were enumerated in a specimen extending only three lines. 

 The colour of the body is either wholly red, speckled red, or with a red 

 line over the site of the proboscis. Some specimens are cream-yellow, 

 with red and white lines intermingled on the back. 



The nature of the food seems to have much influence on the colour, 

 which, if brighter, always fades with time. 



Under the microscope, all the vascular interanea are seen terminat- 

 ing in a fork near the margin. 



This animal spawns in June. The spawn is deposited in irregular 

 quadrangular patches, which are perhaps successively enlarged. 



PLATE XIV. 



FIG. 9. Planar ia ellipsis. 



10. The same, back, enlarged. 



11. Belly. 



12. Another specimen, enlarged. 



13. Head of a specimen, shewing the specks magnified. 



1 4. Arrangement and appearance of the coloured interanea, enlarged. 



15. Spawn. 



16. Spawn. 



c. PLANAKIA FLEXILIS The Flexible Planaria. Plate XIV. Figs. 17, 18, 



19, 20, 21, 22, 23, 24. 



The occurrence of numerous examples since the publication of my 

 former observations, enables me now to add a few essential illustrations 

 to the history of the Planaria flexilis. 



Specimens generally attain six or seven lines in length, by half as 

 much in breadth. But under favourable circumstances, perhaps attain- 

 ing larger dimensions. A large specimen once reached me from a dis- 

 tance, which in vigour must have been at least ten lines in length, and 

 of a pure white colour. The body is extremely thin and flexible, scarcely 



