CLIO BOEEALIS. 



555 



means of these it is informed of the presence of food, and instructed 

 when to uncover the elaborately-organized suctorial apparatus destined 

 to seize it and convey it into the mouth. 



(1485.) The mouth itself is described by Cuvier as being a simple 

 triangular opening, resembling the wound inflicted by a trocar ; and in 

 the solitary specimen at his disposal he did not succeed in detecting any 

 dental structures. Eschricht, however, with superior opportunities, 

 was more successful in displaying the oral organs, and found the Clio 

 to possess jaws of very singular conformation, and a tongue covered, as 

 in many other Mollusca, with sharp horny spines. 



(1486.) One of the jaws removed from the body, and magnified 

 twenty-eight diameters, is represented in the subjoined figure (fig. 

 278, A). It consists of a series of sharp horny teeth of unequal length, 



Fig. 278. 



B A 



A, one of the jaws of Clio borealis. B, the tongue, with its recurved spines. 

 C, cylinder enclosing the prehensile suckers. 



fixed to the sides of a lateral pedicle in such a manner that their points 

 are all nearly at the same level. The teeth themselves have a golden 

 metallic lustre, and, when examined in the sunshine under water by 

 means of a lens, are especially beautiful objects. The basis to which 

 they are fixed is apparently of a fleshy character, and if smashed by 

 being squeezed between two plates of glass, and then placed under the 

 microscope, appears to be made up of a multitude of regularly-disposed 

 fibres that cross each other in two principal directions. 



(1487.) The jaws thus constructed are placed on each side of the 

 mouth, contained in two hollow curved cylinders, the walls of which 

 are muscular ; and if one of these muscular capsules be snipped by 

 means of a pair of very fine scissors, the strangely-formed jaw, with its 

 teeth, is found lodged within it. 



