28 
IOWA ACADEMY OF SCIENCES. 
readily soluble pigments. ” Again he says ‘‘the same coloring 
matters exist in deep-sea animals which are found in shallow 
water forms. ” 
Alexander Agassiz says that there are many “vividly 
colored bathyssal animals belonging to all the classes of the 
animal kingdom and possessing nearly all the hues found in 
types living in littoral waters.”* He notices the scarcity of 
blue color, however, having found it only in an encrusting 
sponge and blue crustacean eggs. The following statements 
are important: “There is apparently in the abysses of the 
sea the same adaptation to the surroundings as upon the lit- 
toral zone. We meet with highly colored ophiurians within 
masses of sponges themselves brilliantly colored at a depth of 
more than 150 fathoms.” “ While we recognize the predomi- 
nance of tints of white, pink, red, scarlet, orange, violet, 
purple, green, yellow and allied colors in deep-water types, 
the variety of coloring among them is quite as striking as that 
of better known marine animals. ” “There is as great a diver- 
sity in color in the reds, oranges, greens, yellows and scarlets 
of the deep-water starfishes and ophiurians as there is in those 
of our rocky or sandy shores. 
“Among the abyssal invertebrates living in commensalism 
the adaptations to surroundings is fully as marked as in 
shallow water. I may mention especially the many species of 
ophiurians attached to variously colored gorgonians, branch- 
ing corals and stems of Pentacrinus scarcely to be distinguished 
from the part to which they cling, so completely has their pat- 
tern of coloration become identified with it. There is a similar 
agreement in coloration in annelids when commensal upon 
starfishes, mollusca, actiniae or sponges, and with Crustacea and 
actiniae parasitic upon corals, gorgoniansor mollusks. The 
number of species of crustaceans * * * colored a brilliant 
scarlet is quite large.” “Large masses of brilliant orange- 
yellow or brownish-pink sponges are constantly dredged.” 
The results of my own observations fully confirm the above 
statements of Agassiz. 
Among the Crustacea we found that a bright scarlet was 
very common, while the remaining species were generally 
either green or pale colored. One remarkable exception was a 
bright blue Solenolamhrus. The echinoderms were particularly 
striking in their colors. Yellow and purple comatulidse 
* “Three Cruises of the Blake,” Vol. 1, pp. 310 and 311. 
