i 



MEMOIRS. 



On the Colouring Matters of Various Animals, and 

 especially of Deep-sea Forms dredged by H.M.S. 

 Challenger. By H. N, Moseley, M.A., Fellow of 

 Exeter College, Oxford ; late Naturalist on board H.M.S. 

 Challenger. (With Plates I and II.) 



During the voyage of the Challenger I made a continued 

 series of observations with the spectroscope on the colouring 

 matters of the various Invertebrata procured by the dredge 

 and trawl. The colours were examined spectroscopically in 

 almost all cases in which an animal presented marked 

 coloration, but usually further attention was only paid in those 

 instances in which a spectrum presenting isolated bands 

 was obtained, such colouring matters being of most imme- 

 diate interest because they are able to be readily identified. 



Observations were also carried on on the colouring matters 

 of shallow water-forms and land animals in continuation 

 of similar work commenced before the voyage was deter- 

 mined on. 



A simple direct vision spectroscope by Baker, of High 

 Holborn, was made use of, consisting of slit, collimator, and 

 compound prism only. The instrument was usually made 

 use of without a microscope. The position of the bands was 

 determined by reference to the solar lines, matters being so 

 arranged that half the field of view was occupied by the 

 solar spectrum, whilst the other half showed the absorijtion 

 spectrum to be determined. 



The following are the observations made on various colour- 

 ing matters. 



Sponges. 



PoLTOPOGON amadou. — A large Hexactinellid sponge, Poli- 

 opogon Amadou (Wyville Thomson), which was dredged in 

 630 fathoms off the Kermadec Islands, showed a bright 

 pinkish-purple colouring of its sarcode. The colour ap- 

 peared to become developed more vividly on the exposure of 

 the sarcode to the air. The colouring matter is soluble in 

 dilute alcohol and fresh water, but not in absolute alcohol* 

 The lokition gave no absorption bands* 



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