seems to be at a palpable disadvantage in the battle of life, yet the
lima is equipped with special apparatus for the maintenance of its right
to live. By the expansion and partial closing of the valves it swims or
is propelled with a curiously energetic, fussy, mechanical action, while
the ever-active pink rays--a living, nimbus--beat rhythmically,
imperiously waving intruders off the track.

The appearance and activities of the creature are such as to establish
the delusion that it is not altogether amicable in its attitude towards
even such a bumptious and authoritative product of Nature as man. Its
agitated demonstrations--whatever their vital purpose may be--to the
superficial observer are danger signals, a means of self-preservation, as
a substitute for the hard calcareous armour bestowed upon other molluscs.
The fussy red rays may impose upon enemies a sense of discretion which
constrains them to avoid the lima, which, though hostile in appearance,
is one of the mildest of creatures. The tentacles, too, have a certain
sort of independence, for they occasionally separate themselves from the
animal upon the touch of man, adhering to the fingers, while maintaining
harmonic action, just as the tip of a lizard's tail wriggles and squirms
after severance.

Most of the blocks of submerged, denuded coral are the homes of certain
species of burrowing molluscs, the most notable of which are the "date
mussels" (LITHOPHAGA). The adult of that designated L. TERES is over two
inches long and half an inch in diameter; glossy black, with the surface
delicately sculptured in wavy lines; the interior nacreous, with a bluish
tinge. This excavates a perfectly cylindrical tunnel, upon the sides of
which are exposed the stellar structure of the coral. A closely related
species (STRAMINEA), slightly longer, and generally of smooth exterior,
partially coated with plaster, muddy grey in colour, adds to the comfort