60 
less the bright colours do not make them as conspicuous in these 
surroundings as they would do in more plain surroundings, and in 
many cases it may be directly protective coloration, as in the case 
of the prawn Stenopus hispidus described by Hickson, or the 
fish Epinephelus hexagonatus as described by Alcock!). (See also 
Doflein, op. cit. p. 203). But f. i. many of the fishes are very con- 
spicuous and not at all to be cited as examples of protective col- 
oration. —— Upon the whole, So far as my experience goes, the 
coral reef fauna does not form such a thoroughly characterized 
community, as do the sand fauna or the other communities men- 
tioned above. While in these all or most of the animals of the 
community are stamped by some common character (like the trans- 
parency of pelagic animals) no such character stamps the coral reef 
fauna as a whole — except its beauty and diversity, which is, at 
least, no very distinct biological characteristic. 
I shall arrange the observations to be recorded in this paper 
after the different classes of animals. 
19 FISKES 
Outside the communities of the fauna's adapted to life on sandy 
bottom, among Zostera and algæ, the Sargasso-fauna and the pe- 
lagic fauna, very few cases of protective adaptation among fishes have 
been recorded. 
One of the most remarkable cases is that of Chætodon pleb- 
ejus recorded by G. A. K. Marshall in his paper on ,The Bio- 
nomics of South African Insects" ”) after observations by Dr. A. 
C. Haddon at Thursday Island in Torres Strait. This little yellow 
fish has the head crossed by a dark, white-bordered, vertical band, 
which includes the eye and tends to conceal it; at the root of the 
tail is a very conspicuous eye-like mark. The fish has the habit 
of swimming for a little distance very slowly tail first, but if 
disturbed it darts off with great rapidity in the opposite direction, 
viz. head first. The probable meaning of this should be that the 
enemies should be induced to regard the tail end as the head and 
the fish thus be saved by darting off in a direction unexpected by 
) A. Alcock. A naturalist in Indian Seas. 1902. p. 103. 
”) Transact. Entomological Soc. London. 1902. p. 375 
