ERE ERE ETS NE Sy, ES ea 
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would. be carried to some considerable distance before becoming 
attached, and would thus be much more widely scattered; it seems 
reasonable to suppose, therefore, that the solitary habit of the 
species of Thalassometridæ is a direct result of the small size of 
their eggs. 
Although as a.… general rule species with large eggs have a 
much more restricted. distribution than those with small, there are 
certain noteworthy exceptions, for instance Capillaster multiradiata, 
which ranges from Madagascar to Japan. But these exceptions 
are confined to strictly littoral species, whereby we at once infer 
that the effect of purely littoral conditions has brought about the 
result, The tides and winds produce,.in the shallow waters along 
the shores, rapid and more or less constant currents which often 
vary from season to season, and which would tend to sweep the 
free swimming larvæ for a much greater distance than they could 
ever cover deeper down in quiet water; thus a species confined 
to the region about the low tide mark might be expected to attain 
an enormous distribution, far in excess of that of closely related 
species with a normally slightly deeper habitat. 
The pentacrinoids of the Comasteridæ are frequently found 
attached to. the cirri of larger specimens, but do not appear to 
attach themselves to any other part of the body, while in some at 
least of. the other families the pentacrinoids are found indiscrimi- 
nately all over the animal. This suggests the possibility that the 
very long combed oral pinnules of the Comasteridæ may be em- 
ployed in clearing foreign particles from the arms and. pinnules, 
a use.to which the oral pinmiles of the other forms are not 
adapted, and that the larvæ of the Comasteridæ are- swept off 
from the more fully grown as soon as their presence is detected. 
That they attach to the cirri may be due to the diminished ;sen- 
sibility: of those organs, or to; the inability of the animals to reach 
them with the oral pinnules. "This idea is strengthened by the 
fact that the parasitic Myzostoma are not found on the arms and 
Pinnules of the Comasteridæ, while they "are very commonly, one 
