-—--—. ^1 V- xxj- - vmf \- ^^- - ^T^i ^- 



^'-. -. 



* -^^♦^^Z-^^_-1^^\-^^.-7j1 _.1^^W- ■^-n^-Ji^^o^ti<^f*¥->-'^^' 



/V 



/ 



252 



STALK-EYED CRUSTACEA. 



; 



vin 



( >T 



J 



IJ 



." J 



«« 



Squilla tenuirostris, from 90 to 100 fathoms, which is a great depth for 

 this shallow-water genus, is deep pink. The more strictly littoral Stomato- 

 pods, on the other hand, although more or less fossoriiil in their habits, often 

 display conspicuous color patterns in various shades of blue, green, and 



brown. 



The deep-sea frees wimining Crustacea consist of the Iloplophorida), cer- 

 tain genera of Peneidge, a few species of Pasiphaeiidso and Sergestida), and 

 the deep-sea Schizopods. Of these, the Hoplophoridic are without exception 

 blood-red, brif>-ht crimson, or crimson lake. The Peneids are mostly red, in 

 a few cases fadin^^- to orange or milk-white. HoMjjorus wqualis (405 fathoms) 

 is pink, Ilaliporus neptunus (1644 fathoms), Aristcms coniscans (561 fathoms), 

 Ilemipeneus carpenteri (1091-1310 fathoms), and Ilejjomadus tener (1310 

 fathoms) are orange colored. Benthesicymits tamieri, a Peneid of a deep 



T 



red ground color, is remarkable for having a large patch of bright blue on 

 the back of the second, third, and fourth abdominal segments.* The deep- 

 sea Pasiphaeiidae and Sergestidae are lurid red or else deep crimson or lake. 

 Amon<->' the Schizopods the various species of G7iathop)Jiaiisia are bright red 

 or crimson. So are Eiicopia and (according to Willemoes-Suhm) the eyeless 

 Petaloplithalmiis, Ceratoniysis spinosa, a bhnd Schizopod from 782 fathoms, 



is milk-white. 



The differences in the coloration of littoral Crustacea that are exposed to 

 different degrees of light are sometimes very striking, individuals of the same 

 species often displaying various tints, according as they live in the open and 

 near the surface, exposed to the fidl influence of the sun, or in deeper water, 

 ensconced under stones or within crevices, and thus removed from the glare 

 of day. The pallor of most fossorial species is very marked, recalling the 

 ghastly appearance of cave inliabitants. 



In connection with the prevalence of red colors among the Crustacea 



from great depths, certain experiments upon shore species arc very sugges- 

 tive. S. Jourdain f has shown that NiJca ediilis, which is brown in a bright 

 light, turns to red when kept in the dark, Ilippohjte varians will change 

 from a lively emerald green to brown, if placed in partial darkness, while in 

 total darkness it assumes a, red huc4 Such experiments as these go far 



4 



toward explaining the prevalence of red color among the Crustacea of the 

 deep sea. It is due to a modification of the pigments, induced by the dark- 



f 





r 



t 



+ 



See page 254. 



Comptes Ecndus, LXXXVIL 302, 1S78. 



Sec A. E. Malard, in Bull. Soc. Philomutli. dc Paris, S^'"^ SScr., IV. 28, 1802 



^ ^ 



f 



