<§>"§> 248, 249. THE CEPHALOPODA. 285 



CHAPTER VI. 



DIGESTIVE APPARATUS. 



§ 248. 



The mouth of the Cephalopoda''' is always surrounded by the arms, 

 (which serve partly as prehensile organs), and by a circular fleshy lip which 

 is fringed or denticulate on its free border. It is, moreover, covered ex- 

 ternally by a thin cutaneous fold having a crucial opening. With the 

 Loligina, there is, beside, a third external lip, arising as a cutaneous fold 

 from the base of the arms ; it has an heptagonal, rarely an octagonal, 

 opening, from the angles of which project longer or shorter tentacular 

 prolongations.® With Nautilus, this lip is extraordinarily developed, — 

 having four considerable prolongations provided with long tentacles.'"* 



Behind these lips is a round pharynx, very fleshy, and armed with two 

 blackish-brown, horny jaws, which move against each other vertically. 



Upon each of these jaws are two large lateral branches which join at an 

 acute angle, thus forming a hooked point. The edges of these jaws being 

 very sharp, the whole has the form of a reversed parrot's-beak, for, the 

 edges of the lower jaw project far beyond those of the upper. '^' ITie 

 pharynx is enveloped by a very complicated muscular apparatus, which 

 arises in part from the cephalic cartilage, and moves the jaws as well as 

 serves in producing the protraction and retraction of the pharynx.*^' 



Between the twO branches of the lower jaw is a Tongue, which is fleshy, 

 and resembles a long swelling adherent to the floor of the oral cavity. 

 Upon its anterior extremity are soft gustatory papillae, and over the rest 

 of its surface there are horny lamellae arranged in regular longitudinal 

 rows, and golden-yellow spines which point backwards. "'^ Its posterior 

 extremity is often folded over, thereby forming a kind of cavity, the open- 

 ing of which is directed backwards, and continuous with a semi-canal lead- 

 ing into the oesophagus. 



§ 249. 



The intestinal canal of the Cephalopoda is wholly without ciliated epi- 



1 I have been unable to find in Hectocotylus tre- given by Fcrussac, loc. cit. According to Ou'cn 



moctopodis, tiie orifice whicii Cuvier (Ann. d. Sc. (On the Nautilus, p. 20, PI. VIII. or Isis, p. 18, Taf. 



Nat. loc. cit. p. 151, fig. 1, 3, 4. f., or liis, 1832, I. or Ann. d. Sc. Nat. p.109, Pl.IV.),withiVa»a7!«, 



p. 5150, Taf. IX., or Froriep^s Notiz. loc. cit. p. 8, the extremities of the jaws are covered with a blu- 



tig. 16, 18, 19, f ) has regarded as a mcuth with isli-white calcareous substance, and the border of 



Hectocotylus octopodis; and as KolUke.r (loc. cit.) the lower jaw is denticulated ; but Valenciennes 



says nothing about a digestive apparatus with (loc. cit. p. 279, PI. XI. fig. 1, 2) has not con- 



these animals, I suspect that it is wanting here, firmed these observations. 



nutrition taking place by cutaneous absori)tioii 5 For this muscular apparatus, see Cuvier, loc. 



while these bodies are in the mantles of theu- cit. PI. III. fig. 3-5, and Anat. comp. V. p. 9 



females. (Octopus) ; and Owen, loc. cit. (Nautilus). 



li See Fcrussac, loc. cit. the figures for Sepia, « Needham, Nouv. Decouv., loc. cit. p. 2S, PI. 



Loli^o, Sepioteuthis, Onychoteuthis, and Om- III. fig. 1 ; Brandt, loc. cit. p. 305, XXXII. fig. 



mastreplies. 6-10 ; Savigny, loc. cit. PI. I.; Ferussac, loc. cit. 



!i See § 243. Octopus, PI. III. Arsionnuta, PI. IV. Sepia, PI. 



•* Cuvier, Uim. p. 25, PI. III. fig. 6 ; Savifrny, IV.; Owen, On the Nautilus, p. 22, PI. VI 11. fig. 



Descript. de I'Egypte, loc. cit. PI. I.; JJelle Cfiiaje, 6, 7, or Isis, p. 19, Taf. II. or Ann. d. Sc. Nat. p. 



loc. cit. Tav. LX. ^0) fig. 9 ; iragner. Icon. zoot. 113, PI. IV.; and Valenciennes, toe. cit. p. 280, 



