PLANARIA. 121 



of the same year, taken from the marsh, September 22. Few were 

 large. Fertile specimens contained four, five, or six brown ova, seldom 

 more, dispersed through the body, and many had none. Where only a 

 single ovum appeared, it was on the right or left side of the body indif- 

 ferently. None of the Planariae survived above a month, nor were any 

 of the ova productive of young. Thus I was disappointed again. 

 This Planaria inhabits few districts. 



g. PLANARIA CUNEUS The Wedge Planaria. Plate XV. Figs. 15, 16. 



This is a minute fresh-water Planaria, somewhat representing the 

 side of a wedge, inhabiting Blackball Pond. Length not exceeding a 

 third of a line. Head obtuse, the corners rounded as it advances, and 

 the portion between them depressed. Body thick, flattened ; tail acute. 

 Colour greyish-brown No eyes visible. Taken in August. 



PLATE XV. 



FIG. 15. Planaria cuneus, enlarged. 



16. The same, magnified. 



17. The same, more highly magnified, 



h. PLANARIA PRASINA Grass-Green Planaria. Plate XV. Fig. 21. 



Length of the largest about half a line ; thickness about the fifth of 

 the length. Body roundish ; head obtuse ; tail tapering to a point. Co- 

 lour beautifully grass-green. Motion active. Several congregate on the 

 side of the vessel containing them. If in a watch-glass they be subjected 

 to the microscope, they will be observed to pass at the edge of the water 

 on the side next the light. One or two brown ova seemed to be in one 

 or two specimens. No eyes visible. 



Drawn up with the roots of the Water Plantain in Blackball Pond, 

 in August. 



Great disparity of size observable among a group. 



PLATE XV. 



FIG. 21. Planaria prasina. 



