Till: CEPHALOPODA. 451 



given off from these ganglia are those which go to the bran- 

 chiae. 



Eyes, olfactory organs, and auditory sacs, are always 

 present. The eyes of the Cephalopoda may be lodge* I in 

 orbital cavities at the sides of the head, as in all the Js&ran- 

 chiata ; or may be pedunculated, as in Nautilus. In t In- 

 former case, the eye is inclosed partly by the cephalic car- 



FIG. ViR. Sepia offlcinilis.T\\e nervous mass which surround? the gullet ; N", the 

 cerebral ; JV, the pedal ; N", the parieto-splauchnic ganglion ; ao, the aorta ; oe, 

 the oesophagus ; (/. buccal nerves ; /". nerves to the anus ; Jtf, pallml nerves ; gr, 

 superior; Q', inferior buccal ganglion. (After Garner.) 



tilage, to which sometimss special orbital cartilages are add- 

 ed, and partly by a fibrous capsule continuous with these. 

 The fibrous capsule becomes transparent over the eye, and 

 gives rise to what is variously interpreted as the representa- 

 tive of the cornea, or as that of the evelids of vertebrated ani- 

 mals. This transparent coat is sometimes entire, or presents 

 only a small perforation (Octopus, Sepia, Loligo, and the 

 other Myopsidce of D'Orbigny) ; sometimes it has a wide 

 opening, th rough which the crystalline lens may project (Lo- 

 ligophes, Ommastrepsis, and the other Oigopsidce of D'Or- 

 bio-ny) ; and sometimes it is altogether absent, and the capsule 

 of the eye becomes an open cup (Nautilus). 



In the Dibranchiata* a great part of the chamber of the 

 capsule of the eye is occupied by the ganglion, into which the 

 optic nerve enlarges after entering it ; by muscles ; and by a 

 peculiar white glandular substance. Lining the capsule, but 



1 " Trans. Linnsean Society," 1836. 



3 See Hensen, u Ueber das Auge einiger Ccphalopoden." (Zit*chrift fur 

 wi&sensckaftlicht Zoologie, 1865.) 



