COLORS OF THE DEEP-SEA CRUSTACEA. 



By Mr. Agassiz's direction, colored drawings of many of the Crustacea 

 secured during the cruise were made by Mr. A. M. Westergren. Some of 

 these are reproduced on Plates A to K of this memoir. The late Professor 

 J. Wood-Mason and Dr. A. Alcock have also published a very full set of 

 notes on the living colors of the Crustacea dredged in the Arabian Sea and 

 the Bay of Bengal by the Indian Marine Survey Steamer " Investigator." 

 So that we now have a knowledge of the color variations exhibited by most 

 of the important types of the deep-sea representatives of this class. It ap- 

 pears from a systematic tabulation of these notes on the colors, that a general 

 tendency is manifested among the Crustacea from deep water to assume red 

 tints, which pass through various shades of pink, orange, and yellow, to sti'aw- 

 color and ivory-white. 



Of eight species of Brachyura, ranging from 90 to 405 fathoms, four are 

 pink, one yellowish red, one pinkish yellow, one straw-color, and one white, 

 with a pink blush. 



Out of twenty-two species of Anomura, coming from depths varying from 

 52 to 1997 fithoms, the majority are some shade of red, pink, or orange, 

 while four species of Munidnpsis (all of them blind, and obtained at great 

 depths, 1310 to 2300 fathoms) are white. It is to be observed that five other 

 species of this genus from lesser depths (117-740 fathoms), although they also 

 are blind like all the species of Munidopsis, are more or less deeply tinged 

 with orange. 



Among the deep-sea bottom sjKcies of Macrura, pink is again the prevail- 

 ing color, — pink of various shades, from a deep purplish pink to milky 

 white, with merely a pink suffusion. Twenty-eight out of thirty-seven 

 species are of this hue, while five are red, one orange, one chalky yellow, 

 and two old-ivory white. 



