58 Oo. A. MAC MUNN. 
colour changing to orange, and bands like those of sp. 3 
were seen. The dark part of Ist band reading from X 589 to 
579, and having a shading on each side of it; the 2nd band 
extended from A 549 to A 523, with its half towards violet more 
shaded than that towards red. 
Sulphuric acid also changed the colour of an alcohol solution 
to orange, and the bands were exactly the same as with nitric 
acid. The acid spectrum could be changed into the alkaline 
one by an excess of caustic soda. 
The residue left by the evaporation of an alcohol solution 
was freely soluble in ether, chloroform, bisulphide of carbon, 
benzene, and water, but insoluble in glycerine. 
The residue became a kind of violet with iodine in potassic- 
iodide, a dirty yellow brown with nitric acid, and a kind of 
orange with sulphuric acid.} 
Examination of Solutions of Other Crinoids.—In 
May, 1887, Dr. P. Herbert Carpenter, F.R.S., kindly sent me 
some solutions in spirit of various Comatule. Owing to their 
age, having been procured on the “ Challenger,” it is not un- 
likely that their contained pigments had become changed. 
However, I here give the results, as they may be useful for com- 
parison with the above. 
* From Station 192, near the Ki Islands. Several species 
of Antedon.” As this solution was very dilute it was evapo- 
rated in vacuo, and left a deep yellow residue. Dissolved 
in alcohol this furnished a yellow solution approaching to 
orange. In this no bands were visible, but it absorbed the 
violet end of the spectrum. The other characters resembled 
those of the pigment of Antedon rosacea. The residue 
became a dark brown violet with sulphuric acid, and was 
hardly changed by nitric acid. 
“From Station 214, off the Meangis Islands. Various 
species of Antedon.” The yellow solution on evaporation in 
vacuo left a kind of purplish-brown residue which dissolved 
in rectified spirit with an orange colour. It strongly absorbed 
1 My spectra differ in some respects from those of Professor Moseley, but 
his description of the reactions agrees with those recorded above, 
