104 PLANARIA. 
power could discern two pair of eyes in each, possibly the rudiments of 
the four clusters belonging to full-grown animals, fig. 25. When with- 
drawn from the dark, the young Planariz rose in great numbers towards 
the surface of the water, congregating on the side next the light—and, 
as mere atoms they were just visible. 
Without equal regularity to the cells of a honeycomb, the vacant 
spawn bore much resemblance to them, fig. 26. 
The Planaria flewilis lives in society, occupying the lower side of 
stones, the crevices of loose shelving rocks, or the cavities of shells, and 
sometimes sinking entirely amidst mud. It must be considered littoral, 
being found rather lower than half tide on a soft muddy bottom. 
The body is extremely thin, and les close to the substances prefer- 
red, from which it may be carefully washed off with a feather while kept 
under water ; or by vitiating the surrounding element, it is forced from 
its haunts to seek a purer medium, and ascending to the surface, it often 
lies there supine. 
Prats XIV. 
Fic. 17. Planaria flexilis, back. 
18. Belly. 
19. Anterior surface, shewing the site and appearance of the specks, 
enlarged. 
. Patch of spawn. 
. Another. 
> 
bo 
. Portion of spawn, enlarged. 
. Portion of spawn, farther advanced. 
bo po by wb 
— 
= 09 
. Young Planaria from the spawn. 
. Young Planaria from the spawn, with two pair of eyes. 
. Empty capsules left by the young, enlarged. 
bo po bo 
Or 
l—) 
d.—PLANARIA MACULATA (ATOMATA ?).—Plate XIV. figs. 27, 28, 29, 30, 
9 9 
31, 32. 
The preceding three species of Planarie can be satisfactorily recog- 
nised as quite distinct. But the tribe is numerous, and the distinguish- 
