122 PLANARIA. 



PLANARIA NIGRA. Ova, Plate XV. Figs. 18, 19. 



The history of this animal is detailed in the Treatise on Planariae, 

 1814. 



The ova are deposited chiefly on the neighbouring vegetable pro- 

 ductions during September, and other seasons of the year. 



PLATE XV. 



FIG. 18. Planaria nigra, ova, as deposited on a blade of grass. 

 J9. Group of ova, enlarged. 



Note. The practical naturalist engaged in a course of observations, 

 is frequently embarrassed by the appearance of animals having some re- 

 semblance to the PlanariaB in several particulars, but without being able 

 to identify them with the genus. 



a. PLANARIA SERPENTCNA, Plate XV. Fig. 20. . 



Length between one and two lines ; body flattened ; head obtuse, 

 enlarging towards each side, and somewhat depressed in the centre of 

 the front, where there seems a circular orifice, probably the mouth. The 

 interaneae, occupying much of the body, of a dark colour, and resembling 

 curving or circular sacs. Colour of the animal white, or grey under the 

 microscope. Motion smooth and gliding as that of other Planarise. No 

 eyes visible. Specimens were taken in July from the pools at Fenton 

 Tower. 



PLATE XV. 



FIG. 20. Planaria serpentina, enlarged. 



b. PLANOIDES FUSCA. Plate XVI. Figs. 35, 36. 



I have been at different times disposed to consider this minute 

 marine animal allied to the Aplysia, or some other genus, always pre- 

 suming that none of the specimens occurring were full-grown. But as 



