THE SCHOOL OF THE SHORE 13 
ger of hard-and-fast statements by the fact 
that there is a frog at Manilla which is often 
seen hopping about on the shore. 
FIsHEs.—The shore-fishes are legion, but 
some are more characteristic than others. One 
of these is the Gunnel or Butterfish (Centro- 
notus gunnellus), so extraordinarily difficult 
to catch because of its power of insinuating 
itself between the stones and into crevices, so 
extraordinarily difficult to hold when one has 
caught it, such is its slipperiness. The father- 
lasher and the sand-eel, the cock-paidle and 
the stickleback are also common on the shore. 
SEA-SQUIRTS.—Fastened to the long flag-like 
seaweeds there are often groups of Ascidians 
or Sea-Squirts, strange degenerate creatures 
which cross the frontier into the backboned 
sub-kingdom in their free-swimming youth, 
but sink back again, as it were, when they 
grow up and settle down. On the stones at low 
tide there are often very beautiful colonies 
of compound Ascidians or Tunicates, quite 
jewel-like sometimes in their fine colouring. 
MOoLLuscs.—Highest in a way among back- 
boneless or Invertebrate animals are the Mol- 
