CONTRIBUTIONS TO ANIMAL CHROMATOLOGY, 57 
observation it was evaporated in vacuo. It left after some 
days’ evaporation a fine red residue, which in thinner parts 
seemed yellow, and had a pleasant smell, recalling that of 
Flustra foliacea. This residue went easily into absolute 
alcohol, forming a fine red solution. A deep layer transmitted 
red only, a less deep gave the bands seen in sp. 1, and a 
shallower still those of sp. 2. These bands gave the following 
readings :—Ist A 598 to A 589, 2nd »A 581 to A 562, and 
3rd in a slightly more diluted solution from A 549 to Xr 
520. 
On adding hydrochloric acid the colour became more 
orange, i. e. less red, and the spectrum changed to that shown 
in sp. 8.1 The bands reading Ist A 589 to X 580, and 2nd, 
probably composed of two bands, from about 549 to A 523, 
the darker part about A 5382—523. 
Ammonia added to an alcohol solution made the colour a 
darker red and caused slight precipitation. A deep layer 
transmitted red only, while in a shallower one a broad, ill- 
defined band in green was seen, sp. 4. When to this solution 
ammonium sulphide was added this band disappeared, but 
no new ones came into view. 
When an alcohol solution was treated with ammonium 
sulphide the fluid seemed redder, and only general absorption 
of all rays except the red was seen. In thin layers a faint 
haze was seen in the green but no bands. 
On treating an alcohol solution with acetic acid it became a 
lighter red, and the spectrum changed as shown in sp. 5, of 
which the bands read :—I1st from \ 597 to A 581 and shading 
to 562, and 2nd in its darker part from A 538 to X 521°5, the 
violet being abruptly absorbed. 
Caustic soda changed the colour of an alcohol solution to a 
darker red, and on diluting still further the colour became 
rose-red. The spectrum was the same as with ammonia 
(sp. 4). 
Nitric acid produced the same effect as hydrochloric, the 
1 In the drawing the first band is shown too near the red; it should just 
touch D, 
