448 
THE OCEAH WOULD. 
to the bill of a parrot, acting transversely, one upon the other. Us 
position is the bottom of a sub-conical cavity, forming the base oi 
numerous fleshy tentacular appendages which surround it, and which 
are termed arms by some writers. These appendages in the gr 0at 
majority of living species are provided with suckers, acetabula (cupping' 
glass-like appendages), by means of which the animal moves at the 
bottom of the sea, head downwards, or attaches itself to its pr 0 )' - 
These suckers are armed or unarmed with a long, sharp, homy claw. 
the unarmed acetabulum, the mechanism for adhesion is well described 
by Dr. l.togct : “ The circumference of the disk,” says this writer, “ 
raised by a soft and turned margin ; a series of long slender folds 01 
membrane covering corresponding fascicula of muscular fibre converge 
from the circumference towards the centre of the sucker, at a shod 1 
distance from which they leave a circular aperture ; this opens ini 0 
a cavity which widens as it descends, and contains a cone of soft 
substance rising from the bottom of the cavity, like the piston of 8 
syringe. When the sucker is applied to the surface, for the purpoS e 
of adhesion, the piston, having previously been raised so as to fill 
cavity, is retracted, and a vacuum produced, which may be s till furthe 1 ' 
increased by the retraction of the plicated portion of the disk.” H ere 
we have an excellent description of the apparatus for holding ° n ' 
When the animal is disposed to let go his hold, according to Profess 01 
Owen, “ the muscular arrangement enables the animal to push forwar 
the piston, and thus in a moment destroy the vacuum which retracti 011 
had produced.” 
In the case of the armed Cephalopods ( Onychoteuthis ), Profess 01 
Owen remarks, “that there are circumstances in which even 
remarkable apparatus described by Dr. Boget would be insufficient t0 
iod 
jile 
mucous-clad fishes more powerful organs of prehension are superadded 
to the suckers, so that in the calamary the base of the piston is, 
remarks, enclosed in a horny hoop, the outer and anterior marg in 
which is developed into a series of sharp curved teeth, which can h 
firmly pressed into the flesh of a struggling prey by the contract ’ 0,1 
of the surrounding transverse fibres, and can be withdrawn by t 6 
fulfil the offices in the economy of Nature for which the Cephalop 1 
was created, and that in species which have to contend with the 
tb 0 
action of the retracting fibres of the piston. “ Let the reader, 
professor adds, “ picture to himself the projecting weapon of the horn? 
