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 Fentacrinirn 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 

 actinias 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. 



Ainong 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 Solenokunbrus. The echinoderms were particularly 

 striking in their colors. Yellow and purple comatulidic 



• Three Cruises of the Blake." Vol. 1, pp. BIO and 811. 



