94 THE FOOD OF ANIMALS 



CARNIVOROUS MOLLUSCS 



CUTTLE-FISHES AND SQUIDS (Cephalopods) 



The members of the highest class of Molluscs, the head-footed 

 creatures embraced under the term Cephalopoda, are essentially 

 rapacious, and typical in this respect are the Cuttle- Fish {Sepia 

 officinalis), the Squid {Loligo vulgaris), the Octopus or Poulpe 

 (^Octopus vulgaris), and the Musky Octopus {Eledone moschatus). 

 In the absence of limbs these creatures possess very effective 

 weapons of offence, formed by modification of a part of the 

 typical molluscan organ known as the foot, and which in its 

 simplest form, as seen in a common snail, consists of a muscular 

 outgrowth from the under side of the body, presenting a creeping 

 sole-like surface. In the case of, say, a cuttle-fish, the front part of 

 this foot has grown round and fused with the head, hence the name 

 head-footed molluscs. And this region is drawn out into a number 

 of slender arms capable of being stretched out till they look like 

 whip-lashes, there being eight of them in an octopus and ten in a 

 cuttle-fish. In the latter, two of the arms are much longer than 

 the rest and expanded at their ends, while they can also be 

 drawn back into special pouches. The mouth of the animal is 

 situated between the bases of these arms. (See vol. i, fig. 179.) 



Not only are the arms extremely extensible and capable of 

 being twined around any animal attacked, but they are studded 

 on their inner sides with suckers (stalked in cuttle-fishes, unstalked 

 in octopi), by means of which a most tenacious grip is maintained. 

 Each sucker is a little cup, the margin of which is provided with 

 a toothed horny ring for the prevention of slipping, and within 

 which is a muscular projection that can be drawn back piston-like 

 so as to produce a vacuum. After being seized by the arms the 

 prey is drawn to the mouth, which is furnished with a pair of 

 strong horny jaws closely resembling the beak of a parrot (fig. 

 376). After this has fixed itself firmly to the body of the animal 

 the rasping organ is brought into action, and this structure is so 

 important that it merits a somewhat detailed description. 



A rasping organ, or, to use the technical term, odontophore 

 (Gk., odous, odontos, tooth; phero, I bear), is eminently character- 

 istic of all the Mollusca, with the exception of the bivalve forms, 

 and is just as useful to the vegetarians as to the carnivorous 



