118 Animal Life 
a much-chastened spirit. 
Should, however, the acquisi- 
tion of specimens be an 
important object, the enlisted 
services of the wily native— 
who needs but a little paint 
and a pearl-shell for the 
renewal of his full-dress 
apparel—will speedily secure 
an abundant supply. 
A remarkable circumstance 
associated with the life 
economy of Periopthalmus 1s 
the fact that 1t cannot sustain 
life if continually water-sub- 
merged like ordinary fish. 
The exposure of its tissues 
SATIS ENT IS: to the action of atmospheric 
WiSGNG: GYSIEL alr with every fall of the tide 
appears to be essential to its 
well-being, and examples experimentally kept under water for prolonged intervals were 
literally drowned. As a provision for its abnormal life-habits it has been ascertained 
that Periopthalmus possesses a supplementary respiratory organ which, singularly to relate, 
is represented in this instance by the creature’s tail. The fish while reposing on the 
surface of the mud commonly leaves its tail more or less immersed in the water. The 
blood circulates with abnormal energy through 
this thin membraneous appendage which 
accordingly fulfils the function of a supple- 
mentary gill. 
Some queer comrades commonly share 
the recesses of the mangrove thickets with 
Periopthalmus. These are the so-called 
Mangrove Fighting or Calling Crabs. The 
North-Western Australian species is notable 
for its brilliant livery of black and scarlet, 
while tints of orange, pink, or blue may be 
variously blended in allied forms. The huge 
relative size of one of the large claws or chele 
in the male individual is the distinguishing 
feature of these peculiar crabs, and being 
held aloft in a menacing or beckoning manner 
as the creature walks, has obtaimed for 1 in 
conjunction with its eminently pugnacious 
habits its characteristic popular titles. 
Fish and crabs are found consorting 
with one another in tropical Australian wate-s 
under yet more singular conditions. The | “SS. , 
camping-ground of both the fish and crab is, — From a Photograph by W. 
in one instance, in place of a mangrove AMPHIPRIONS. 
swamp, on the expanded disk or among the Commensal guests of a Giant Anemone that sleep and 
ae ; shelter among the Anemones’ tentacles, but sport and 
crowded tentacles of a Giant Sea Anemone. feed among the adjacent coral thickets. 
Saville-Kent, F'.Z.S. 
