CONTRIBUTIONS TO ANIMAL CHROMATOLOGY. 89 
lipochrome. This lipochrome is practically identical with that 
of Astacus, and therefore requires no further description. I 
may add that the lipochrome present in the “ liver ” was found 
to be identical with that of the hypoderm. 
In Pagurus bernhardus a one-banded red lipochrome 
occurs in the same situation, agreeing in every essential respect 
with that of Astacus and Homarus. 
In Cancer pagurus a similar lipochrome is present in the 
hypoderm, but in the shell of this species I have found 
a chlorophylloid pigment. ‘The shell was decalcified 
with diluted hydrochloric acid, washed free from acid, dried, 
and then extracted with chloroform ; after a week’s extraction 
the chloroform had become yellow and showed the spectrum 
of “acid chlorophyll.” The chloroform left on evaporation a 
dirty green residue, which when dissolved in rectified spirit 
also showed the spectrum of acid chlorophyll. Here, again, is 
an instance of the deposition of the enterochlorophyll of the 
“liver” in the shell. I find, however, that this occurrence of 
chlorophyll in the exoskeleton of C. pagurus is exceptional, 
but in this case “the exception proves the rule,” and such 
isolated facts are of extreme interest in enabling us to under- 
stand the uses of enterochlorophyll. 
Carcinus mezenas.—The shell decalcified by hydrochloric 
acid (dilute) was washed with water, dried, and treated with 
chloroform. This extracted a red lipochrome which when 
dissolved in alcohol, ether, chloroform, bisulphide of carbon, 
&c., absorbed all but the red and a little green in a deep layer, 
while in a shallow one, one broad band became detached in the 
green, with its half towards violet more deeply shaded than that 
half towards red. The residue gave the lipochrome reactions 
with sulphuric and nitric acids. If we compare these crustacean 
lipochromes with those met with among starfishes, we find that 
the former are more like rhodophan, while the latter are more 
like chlorophan in spectrum, though differing in colour. 
There is no doubt that in many cases chromogens are 
present which on very slight provocation change into these 
lipochromes, either by dehydration, oxidation, or by some 
