20 



On the side of the funnel next the oral sheath, there are two small but 

 distinct muscles (levatores infundibuli) {(j. g. pi. 2.), which, in addition to their 

 use in drawing the funnel towards the head, appear to be connected with the 

 play of the tongue-Uke valve with which it is provided. They are rather 

 more than an inch in length, and are round and slender in form ; arise from the 

 cartilaginous processes at the base of the funnel ; pass foi-wards in smooth canals 

 in its lateral parietes, and expand to be inserted into its extremity. This extre- 

 mity they will draw away from the valve, in consequence of the extreme thinness 

 of the parietes of the funnel anterior to the attachment of the valve, and so 

 insure the exposure of that surface of the valve previously in contact with the 

 ftinnel, to any opposing current from without, whose entrance by the funnel it 

 is designed to prevent. 



Analogous muscles are present in Octopus, Sepia, and Loligo ; but they form 

 in these genera part of the parietes of the funnel, and are not inclosed in canals. 

 They are most distinctly developed in Loligo vulgaris, and are in that animal 

 united together prior to their insertion into the extremity of the funnel. 



§ 3. Of the Digestive System. 



As the remaining muscles in this animal are chiefly connected with the pre- 

 paratory organs of digestion, they may be conveniently treated of under this 

 head, and be preceded by a description of the jaws (n. o. pi. 4 ; tig. 2. 3. 4. 5. 

 pi. 8.). 



These are two in number, having a vertical motion, and resembhng in form 

 the bill of the Parrot reversed, the upper mandible being encased in the lower 

 when closed : they are adapted posteriorly to a muscular basis, to which they 

 owe their motions. Thus far they resemble the mandibles of the Dibranchiate 

 Cephalopods ; but they are not composed entirely of horny matter, nor are they 

 uniformly of a brown or black colour, their extremities being of a dense cal- 

 careous nature, and of a blueish white colour ; they are also less pointed at the 

 end ; and the oral margins of the lower mandible are notched and dentated. 



They are proportionally larger than in the Cuttle-fish, each mandible measuring 

 in length one inch and three Unes, and in vertical breadth one inch. About 

 half an inch from their anterior extremities the horny part separates into two 

 lamins, the exterior of which in the upper mandible (a. fig. 2. 3. & 5. pi. 8.) is 



