336 SEA MONSTERS UNMASKED. 



organs like those of the snail, as the octopus has organs 

 like those of the shell-bearing argonaut, has no shell. The 

 cuttles and squids may be compared to some of the sea- 

 slugs, as Aplysia and Bullcea, and to some land-slugs, as 

 Parmacella and Limax, which have an internal shell. 



fhe argonaut and the other families of the cephalopods 

 do not come within the scope of this treatise ; we will there- 

 fore confine our attention to the three above mentioned. Of 

 the anatomy and homology of the Octopus, Sepia, and Cala- 

 mary we need say no more than will suffice to show in what 

 manner they resemble each other, and wherein they differ, 

 in order that we may the more clearly perceive to which of 

 them the story of the Kraken probably owes its origin. 



The octopus, the sepia, and the calamary are all con- 

 structed on one fundamental plan. A bag of fleshy 

 muscular skin, called the mantle-sac, contains the organs 

 of the body, heart, stomach, liver, intestines, a pair of gills 

 by which oxygen is absorbed from the water for the puri- 

 fication of the blood, and an excurrent tube by which the 

 water thus deprived of its life-sustaining gas is expelled, 

 The outrush of water with more or less force, from this 

 " syphon-tube," is also the principal source of locomotion 

 when the animal is swimming, as it propels it backward not 

 by the striking of the expelled fluid against the surrounding 

 water, as is generally supposed ; but by the unbalanced 

 pressure of the fluid acting inside the body in the direction 

 in which the creature goes. Into this syphon-tube, or 

 funnel, opens, by a special duct, the ink-bag ; and from it 

 is squirted at will the intensely black fluid therein secreted. 

 I doubt very much the correctness of the statement 

 mentioned by Pontoppidan and others, that the cuttle 

 ejects its ink with a desire to lie hidden and in ambush 

 for its intended prey, or with the intention to attract fish 



