ON COLOURING MATTERS OF VARIOUS ANIMALS. 
17 
Antedonin, found in certain Holothurians as well as in 
Antedon. 
Iloplacanthinin. 
Crustaceor ubrin. 
Aplysiopurpurin (the same probably in Doris). 
Ianthinin. 
No doubt the list is capable of much furthur extension; 
Besides haemoglobin, the distribution of which is so wide 
and yet so partial (Lankester, c Proc. Royal Soc.,’ No. 140, 
1873), and bile pigments, peculiar colouring matters giving 
absorption spectra have now been found to exist in members 
of all the seven groups of the animal kingdom. Amongst 
Protozoa such colouring matters occurs in Infusoria and 
Sponges ; amongst Ccelenterata they occur both in Anthozoa 
and IlydromedusiE, in Echinodermata in both Crinoidea, 
Echinoidea and Ilolothuroidea, but not in the Asteroidea. 
In Vermes, in Annelids and Gephyreans. In Arthropoda, 
in Crustacea and in Insecta. In Mollusks, in Gasteropods 
only. In Vertebrata, in four lish, three species of Odax, 
and one Labricthys, and twelve birds 1 of two closely allied 
genera. The Echinodermata and Ccelenterata appear to be 
the groups which are most prolific of such colouring matters. 
The apparently capricious restriction of these colour¬ 
ing matters to certain parts only of the animals possessing 
them has been dwelt on by Professor Lankester (/. c.). 
In the case of haemoglobin such instances, as its restric¬ 
tion to the pharyngeal muscles of certain Gasteropods, and 
the nerve-ganglia of Aphrodite aculeata, may be cited, as also 
its occurrence only in the muscles of the dorsal fin of Hip¬ 
pocampus amongst the muscles of that fish. I may add an 
observation of my own of a somewhat parallel case to this 
latter, viz. that in sharks of the genus Garcharias, of which 
many were caught and skinned on board the Challenger, a thin 
layer of muscles next the skin, and closely adherent to it, 
is tinged of a deep red colour with hemoglobin, appearing 
like mammalian muscle, whilst all the deeper layers of 
muscle forming the main mass of the body are pale and almost 
white. In a Garcharias brachiurus caught off the Ker- 
madee Islands this red layer of muscles was not more than 
a quarter of an inch in thickness. Mr. Lankester accounts 
for the presence of the haemoglobin in the muscles of the 
dorsal fin of Hippocampus by the special activity of that 
organ, but such an explanation fails in the case of the shark, 
1 During tlic voyage of the Challenger I believe 1 saw a notice in some 
scientific periodical to the effect that turacin had been discovered in an 
Australian parroquet. I cannot find the statement again. 
2 
