320 CAENIVOROUS MOLLUSCA. 



tentacula are two feet and a half, and as slender as a thread ! 

 The like is not to be found exampled among organized 

 creatures, for these tentacula have no analogy with the fila- 

 ments of annulose animals ; and the filaments which dangle 

 from the Physalia and certain Medusae possess none of 

 their organic importance, and are neither fitted for, nor 

 applied to, similar purposes. In the Loligopsis the tenta- 

 cula are garnished all along the stalk with minute sessile 

 suckers, which, as usual, become larger on the clavate extre- 

 mities. How these slender organs are moved, how their 

 motions are propagated along the lengthened line, how the 

 club at the end of such a flexible line is supported, and 

 how the organs are preserved from amputation or injury, are 

 all questions which start upon us as we contemplate the 

 creature, and to which it is not easy to give a satisfactory 

 answer ; for you must further know that these elongated 

 tentacula cannot be retracted and hidden in a cephalic cavity 

 as I have told you can be done with those of the Loligo and 

 Sepia, there being no such cavity in this anomalous species. 

 To account for the movements of the organs, it may be con- 

 jectured that the longitudinal muscular fibres in their com- 

 position are susceptible of partial contractions in any point 

 of their course as the animal may will ; and if we further 

 suppose that every cup along their stalk is a centre of at- 

 tachment to these fibres towards which they may contract, 

 we get, in fact, a series of short independent muscles, under 

 whose play the tentacula may be stretched out or inflected, 

 or spreada broad or brought into nigh contact, and fixed to 

 and around any prey that may be floating careless at a dis- 

 tance, and unconscious of danger from such a foe ! * 



" The animals which we have thus seen to be endowed 

 with so various and formidable means for seizing and 

 overcoming the struggles of a living prey are provided 

 with adequate weapons for completing its destruction, and 

 preparing it for deglutition." The digestive system of 

 the class, however, is less uniform in structure than, from 

 the sameness of their food, we might at first suppose ; 

 but, in sketches of the very general character to which 

 I limit myself, I pass over the peculiarities of tribes, 

 to notice little beyond what is common to the class. 

 The mouth, formed by a puckered fold of the skin, is 

 placed at the base, and in the centre of the circle formed 

 by the feet, and is armed with two powerful corneous 

 jaws, having a vertical motion : they are fashioned to the 



* Ferussac in Ann. des Sc. Nat. n. s. iii. 341-3. 



