390 



MOLLUSC A. 



Fig. 390. — Anatomy of Octopus vulgaris, a, amis; tio, aorta: ct\ vena cava with ne- 

 phi'idial appendage ; rf, intestine ; go, optic ganglion ; /i, S3'stemic lieart ; (. nrop ; 

 K, head ; k, ctenidia ; kli, branchial heart ; kn, cartilage; /, (', liver and gall duct, 

 the liver indicated by dotted line; il/, mantle; o, ovary ; od, oviduct; p. pedal 

 ganglion ; s buccal mass with salivary glands; st, stellate ganglion ; sy, stomach 

 and sympathetic ganglion ; T, basis of tentacles ; t, ink sac ; c, visceral ganglion: 

 vk, auricle of systemic heart ; *, spiral blind sac. 



glia, of the nervous system (fig. 301). A 

 single dorsal mass represents tlie cerebral 

 ganglia; connected with this by broad com- 

 missures, the pedal and visceral (viscero- 

 pleuro-parietal) ganglia lie close together 

 ventrally. With these parts are associated 

 upper and lower buccal ganglia. The large 

 optic ganglia, developed in the optic nerve 

 arising from the cerebrum, are especially 

 characteristic of the Cephalopoda, as are the 

 ganglia stellata, right and left at the anterior 

 Fin. 391.— Nervous system edge of the mantle (fig. 31)0), which owe 

 ihe*si'ife."-'^,;l'("'inf'er'ior their name to the radiation of fibres to inner- 



Juiccal ganglion; gJ 

 perior buccal gan 

 gc, cerebral ganglio 

 pedal ganglion ; gi\ vis- 

 ceral ganglion ; mJi, buc- 

 cal maws; ir\ a?sophagU8 ; 



perTor' ^ucfl^ gk&n; vatc the mantle. All unpaired sympathetic 

 i;^dlTtangilo"f »." Vf: ganglion lies at the junction of stomach and 

 cerai ganglion ; wh, buc- ]j][^^^ g.^e. Cerebral, pedal, visceral and optic 

 op, optic ganglion. ganglia are enclosed in the cephalic cartilage. 



