STAR-FISHES, SEA-URCHINS, ETC. 
353 
de-mer soup is held in high favour, and its more 
extensive introduction onthe menu-cards of Western 
civilisation may be only a question of time. 
Many species of sea-cucumbers inhabit British 
seas, but none possess that density of tissue which 
is essential for their economic conservation ; the 
majority, moreover, are of comparatively small size, 
some few inches long only when fully extended, 
whereas the commercially valuable tropical ones may 
measure as much as from 2 to 3 feet. The mode of 
feeding of sea-cucumbers is somewhat interesting; 
the smaller species, with much-branching tentacles, 
generally affix themselves by their tube-feet to 
some object, and, extending their tentacles in all 
directions, utilise them, like those of a sea- 
anemone, for seizing any minute and suitable prey 
which may strike against them. The microscopic 
organisms on which they chiefly feed abound in 
the waters they inhabit, and one after the other, 
the branched tentacles having effected a capture, 
are gathered together and tucked bodily into the 
creature’s central mouth and apparently half-way 
down its throat. The larger coral-frequenting 
species are provided mostly with mop-shaped 
tentacles. They crawl about leisurely in search of 
their food, mopping over the ground, and gathering 
up in their tentacles the minute shells and other 
organisms on which they subsist, which are col- 
lectively thrust with an indrawn tentacle into the 
Photd by W. Saville-Kentf F,Z,S,'\ [^Milford'On~Sea 
A BRANCHING-ARMED BRITTLE-STAR 
The specimen is attached to a brilliant scarlet sponge 
throat. In some of the lower forms the tube- 
feet have disappeared, the integument is thin 
and semi-transparent, and the worm-like animal 
crawls about by means of its skin-spinules, 
which take the form of anchors or grappling- 
hooks. In an opposite direction they may 
develop a supplementary covering of dermal 
plates and a more rigid integument, which 
indicate their nearer relationship with sea- 
urchins. 
The majority of sea-urchins and star- 
fishes pass through a series of interesting 
metamorphoses before arriving at the adult 
state. The larval phases in these instances 
are free-swimming organisms, having arm-like 
processes, strengthened by calcareous rods 
that have been likened in contour to a clock- 
stand. A small spherical central area, like a 
clock in its case, representing the stomach of 
the larva, develops spicules around it, and 
becomes the body of the urchin, the other 
Ph,t$ hy IV. SaoilU-Ktnt, F.Z.S. 
SEA-CUCUMBERS, SOME WITH 
EXTENDED TENTACLES 
ai W est .Australian species ’whose colours are bright pink and yellow 
