182 THE WORLD OF THE SEA. 
glide over the surface of the waters in undulating curves. The 
little voyagers contract and expand simultaneously, manceuvring 
CHAIN OF PHOSPHORESCENT SALPAS ON THE SURFACE OF THE SEA. 
in concert, like a company of admirably-drilled soldiers; indeed, the 
whole line acts as one individual. Sailors call them the sea-serpent. 
They always swim upon their backs, and the mode of their 
A’ SOLITARY SALPA. 
(Salpa Democratica.) 
locomotion is very peculiar. They drink in a quantity of water, 
which they squirt out from their other extremity ; and so their 
body is pushed on by the recoil. This is a wonderful mode 
