228 Prof. W. C. M‘Intosh on the 
Palolo takes place for its pelagic stage, and the hues of the 
pelagic phases of the Nereides are likewise vivid. The 
colours of the pelagic young of the sedentary forms, such as 
Sthenelais, are often brightly coloured. 
Aunelids which perforate hard substances, as Polydora and 
Dodecaceria, are coloured equally with the free, and the pelagic 
phases of the latter retain vivid tints. 
‘The Nemerteans and other Turbellaria, with a few excep- 
tions, such as Nemertes carcinophila, are often of a colour at 
variance with their surroundings—and the same may be 
said of the Leeches; but the Gephyreans, especially those 
frequenting mud, are generally inconspicuous, though Bo- 
neltia is green. The marine Planarian EHurylepta vittata 
between tide-marks is conspicuously banded with brown and 
yellow, and others are similarly variegated with red, purple, 
and yellow. Many, however, are of a uniform colour and 
often resemble their surroundings. As anemones and fishes 
prey on them, their colour would not seem to be protective, 
either in the sense of corresponding with their environment 
or acting asa warning to predatory forms. Mr. Punnett tells 
of a small Nemertean parasitic in an Ascidian which is 
brightly striped, and larger free species are similarly banded. 
Borlasia Elisabethe, which is boldly blotched with purplish 
brown and white, lives in a tube of mud under stones in 
Herm. 
The coloration of the sexes in the Crustaceans is often 
similar, as in the common and the Norway lobsters, though 
in some (e. g. the shore-crab) there are marked differences. 
Yet after all what selection can a female shore-crab exercise 
when the courting is carried on when she is in a soft and 
helpless condition immediately after casting her shell? The 
minute complemental males of certain Cirripedes afford 
similar data. 
‘The evidence in regard to protective coloration is some-_ 
what ambiguous. On the one hand, Prof. Moseley states 
that the Crustaceans (Vautilograpsus) tound on the gulf-weed 
resemble it in tints, even to the white patches which imitate 
those of Membranipora and the sea-acorns (Balant). He 
also records a similar crab of a blue hue on the float of 
Janthina, Portumnus variegatus somewhat resembles the 
greyish hue of the sand amongst which it lives. ‘he colora- 
tion of the stalk-eyed crustaceans is often curiously compli- 
cated by parasitic growths, such as alge and zoophytes. 
kiven the slender Stenorhynchus rostratus has its dorsum and 
limbs enlivened by tufts cf U/va or by Plumularia, Campanu- 
farta, patches ot /falichondria, and the tubes of Terebelle. 
