1895.] 



.UfATOMT or XAUTILUS POilPILIUS. 



675 



swells out slightly, forming the buccal ganglion {huc.g.). From 

 this pass backwards two nerves into the sponge-work of the 

 pharyngeal wall {ph.n.). Whether they are continued back in this 

 along the sides of the crop to become connected with the gastric 

 ganglion, I was not able satisfactorily to determine. From the 

 aboral end of the buccal ganglion anteriorly a twig passes to a 



Fig. 4. 



cja~- 



ph.g 



buc. phar.con 



b.com 



ph n 



Buccal nervous system of Nautilus pompilius. 



ph.g, pharyngeal ganglion ; huc.g., buccal gauglion ; o.c, cerebro-pharyn- 

 geal connective ; buc.phar.con, bucco-pharyngeal connective ; ph.n, 

 pharyngeal nerves ; b.oom, buccal commissure ; ant.com, anterior 

 pharyngeal commissure. 



large elevation of the buccal lining, within which it divides up into 

 numerous branches. At its oral end the ganglion passes into the 

 short convex-forwards commissure which connects it with its 

 fellow. From this two nerves pass adorally on each side, the 

 smaller more mesially situated immediately underlying the radula. 



V. The Innervation of the " Inner Inferior Lohe^ 



Posterior (ventral) to the buccal mass, well within the hood- 

 tentacle complex, is a flattened lobe, bearing on each side a 



43* 



