438 Dr. Johnson's observations on the genus planaria. 
Long . 6 tin. Lat. 2 lin. 
Body, brown on the back ; grey or whitish on the belly ; 
slightly convex above, plain beneath ; truncate before, pointed 
behind ; iris, white ; two ventral foramina ; eyes, two, black, 
in a white areola. 
P. brunnea. 
Planaria oblonga brunnea, linea longitudinali nigra. 
Long. 5 lin. Lat. lin. 
Body, dark brown, with a black dorsal longitudinal line ; 
convex above, plain beneath ; obtuse before, slightly pointed 
behind ; two ventral foramina ; numerous eyes. 
P. lac tea. 
Planaria depressa, oblonga, alba, antice truncata. 
Long. 6 lin. Lat. 2^ lin. 
Body, milky-white, or cream-colour; slightly convex 
above, plain beneath ; truncate before, sharply pointed be- 
hind ; lateral margin acute, pellucid ; two ventral foramina ; 
eyes, two, deep black. 
These little animals, which are delineated of their natural 
size, in Fig. 1, 2, 3,4, are generally found in slow streams, 
assembled together in clusters, attached to the roots, or under 
surfaces of the leaves of aquatic plants, pieces of wood, stone, 
&c. In a state of rest, they are of a circular or spherical 
shape ; when in motion, linear. They are remarkably quick 
and rapid in their movements, and contract and lengthen 
themselves with the greatest facility. From their great con- 
