156 NEREIS. 
back, under the reflected leaves, enlarged, fig. 16. Four black eyes, dis- 
posed in two pair, stood in a line across the head, fig. 17. 
About ten segments, gradually diminishing in breadth, first consti- 
tuted the renovating part, terminating by an enlarging trumpet as a’ pro- 
minent thick margin, fig. 18. In three months the renovating segments 
had multiplied considerably. 
Probably fig. 11 had been mutilated. 
Colour of the animal reddish ; the upper edge of the blade vivid, 
under edge yellowish. 
These animals swim by violent contortions. They form a slight 
tube of earthy and fine sandy particles, wherein they repose long, and 
always below. Marine. 
Prats XX. 
Fic. 11. Nereis foliata, Leaf or Blade Nereis. 
12. Head, upper surface, slightly enlarged. 
13. Head, under surface. 
14. Blade or leaf, enlarged. 
15. Smaller specimen or variety. 
16. The same enlarged. 
17. Head, enlarged. 
18. Posterior extremity, enlarged. 
§ 11. Neruis contorra—The Spiral Nereis —Plate XX. Figs. 19, 20. 
Length half an inch. Body round, slender, composed of numerous 
segments. Two large and long cartilaginous-looking antenne on the 
head. A pencil of bristles issues from a papilla on each side of the seg- 
ments, together with a spine of some length towards the back. 
No eyes could be discovered. 
This animal generally lies in so close a coil, that it is very difficult 
to ascertain its true figure, especially that of the posterior part, which 
has a short funnel-shaped margin. 
