532 



CEPHALOPODA. 



In Onychoteuthis the inner lip (d, Jig. 218) is 

 tumid, and merely subplicated ; the angles of 

 the external labial membrane are extended 

 along the middle of each foot for a short dis- 

 tance. In Sepia the inner lip is fringed, as in 

 Nautilus. The outer lip is tied down by mus- 

 cular bands to the bases of the arms, but sends 

 forward eight short, conical, unarmed processes. 

 In Loligopsis and Cranchia the outer-lip sends 

 off a muscular band to the base of each arm, 

 but has no free processes. In Octopus the 

 suckers commence immediately round the mar- 

 gin of the oral aperture, which is so con- 

 tracted that the mandibles can seldom be seen 

 without dissection : the 

 inner-lip is fimbriated, as in 

 Sepia. In Qcythoi it is 

 tumid and entire, but pli- 

 cated both circularly and 

 transversely. 



The tongue is a large and 

 complicated organ, and is 

 constructed on the same 

 plan in both orders of 

 Cephalopods. In the Nau- 

 tilus it is supported by an 

 oblong horny transversely 

 striated substance, which 

 appears to represent the 

 body of an os hyoides (a, 

 jig. 236.) The posterior ex- 

 tremity of this substance is 

 free, or connected only by a few filaments with 

 the parts above, but its anterior extremity is 

 embraced by a pair of retractor muscles (6), 

 which originate from the posterior margins of 

 the lower mandible. The fleshy substance of 

 the tongue, thus supported, is produced ante- 

 riorly, and forms three caruncles (c), very soft 

 in texture, and beset with numerous papillae, 

 having all the characters of a perfect organ of 

 taste. The anterior or terminal caruncle is the 

 largest, and four delicate retractor or depressor 

 muscles (d) are inserted into it. Behind the 

 caruncles the dorsum of the tongue is encased 

 with a thin layer of horny matter, about five 

 lines in length, from which arise four longitu- 

 dinal rows of slender prickles (e), which are 

 from one to two lines in length, and are in- 

 curvated backwards. The number of these 

 prickles is twelve in each row, singularly cor- 

 responding with the number of tentacles given 

 off from the labial processes. 



It is unnecessary to allude to the obvious 

 utility of this structure in seizing the morsels 

 of food, and directing them towards the gullet, 

 after they have been broken up by the mandi- 

 bles. Behind this horny part the tongue again 

 becomes soft and papillose ( t /), but the papillae 

 are coarser and larger than those on the anterior 

 portions. Two broad fleshy processes (g, g,) 

 project forwards from the sides of the fauces : 

 these also are papillose, and are perforated in 

 the middle of their inner surfaces by a small 

 aperture (h, A), which leads into a glandular 

 cavity, situated between the folds of the mem- 

 brane, and analogous to the superior pair of 

 salivary glands in the Poulp, Calamaries, &c. 



In the Dibranchiate Cephalopods the tongue 



Fig. 218. 



Section of the Beak, with the Tongue of an Onychoteuthit. 



is similarly composed of an anterior and pos- 

 terior papillose and a middle spiny portion. 

 In the specimen from which the figure (218) 

 was taken, the anterior fleshy portion (e) 

 was slightly divided into three parts, but was 

 retracted by a single round muscle, and the 

 papillae were relatively fewer and coarser than 

 in the Nautilus : at its sides there were several 

 orifices of glandular follicles. The horny plate, 

 covering the middle part of the tongue, is bent 

 at right angles ; the recurved hooks in the 

 Onychoteuthis are confined to the anterior and 

 vertical surface ; they commence above or be- 

 hind in seven rows ; but, as they descend, first 

 the two outer on each side blend together, and 

 then each united row joins the next, so that 

 there remain but three rows at the lower part 

 of the sheath. In the Cuttle-fish the seven 

 rows of lingual spines continue distinct. 



In the Onychoteuthis the posterior portion 

 of the tongue (g) is inclosed, as in the Nau- 

 tilus, between two faucial or pharyngeal folds 

 of membrane (A, A), but their inner surfaces, 

 instead of being merely papillose, are beset 

 with rows of small recurved spines, which 

 must greatly assist the act of deglutition. 



The superior salivary glands (z) are not con- 

 fined to the outside of the buccal mass, as in 

 the Octopus, but extend between the layers of 

 membrane which form the pharyngeal fold, 

 forming here a flattened mass (z) ; their duct 

 opens at the bottom of a longitudinal fissure on 

 the inner surface of the fold ; styles are repre- 

 sented passing into the ducts of these glands 

 in the figure. 



In most of the Dibranchiata a second and 

 generally larger pair of salivary glands are 



