60 PHYSIOLOGICAL SERIES. 



D. 62. The central nervous system of a < 'tittle-fish (Sejtia officin- 

 <!//.<), isolated to -how the relations of its parts, the origin 

 of the main nenes. ami the anterior portion of the vix-.-ral 

 system. 



The pointed anterior extremity ol' the cerebral ganglion 

 is joined hv a pair of connectives to a small independent 

 Jion (supra- pharyngeal), which is probably a dis- 

 connected piece of the cerebral ganglion and not a part of 

 the visceral svstein. Thi- ganglion is situated on the dorsal 

 surface of the o'sophagu- close behind the buccal mass, and 

 innervate- the peri-tomial membrane by a number of nerves 

 that radiate from its anterior margin. It is united to the 

 anterior part of the BuboMOphageal mass by a pair of 

 connectives that ri-e from its posterior surface, and by a 

 nd pair from its outer extremities to a buccal ganglion 

 that lies below the (esophagus on the posterior wall of the 

 buccal mass. Nerves from this latter centre supply the 

 buccal ma, radula, ami alimentary canal. 



The errehral ganglion is further united by connect ive- to 

 the mbOBSOpbageal mass. There are two on either side a 

 -mall one that ari-es from its anterior ext reniity and joins 



the snprapbaryngeoHraboesophageal connective close to the 



SaboBAOphageal ma-s, and another, extremely short and 

 -tout, that form- the lateral part of the OtrCUm-OBSOphagea] 

 ring below the optic stalk. This last is .-uperlieially >in^le, 

 but internally two tibroii- >l rands can he distinguished that 

 j.a-- re-jpcdively to the anterior and po-lerinr part of the 

 8ubtr-o|.ha-- ; ,l ma--, and represent cerebro-prdal and 

 'nri)-|'leiiral connectives. The subn'sopha^eal ma^s 

 may he divided into an anterior and a po-lcrior region. 

 The anterior innervate- the arm- and lore part of the 

 funnel, and may be regarded a- a pedal v;:mglion. The 

 rior region contain- the pallial and vi-ceral centre-: ii 

 j.roje.-t^ backward* beyond the cerebral ganglion and gixes 

 .,tV three large |-air- of nerv- n-|..-etivcly to the mantle, to 

 the posterior part of the funnel, and to the \ iaoen and gills; 

 two Mnaller pair- ari-e trom it- dor-al and ventral Mii-faces 

 and innervate the -uj-erlicial part- of the eves. 



O.C. i:$06F. 



1'eUei r. Arch. Uiol.. t. viii. l.s.ss. p. ( 



