38 



are small and numerous ; they penetrate, at a short distance from their origin, 

 the substance of the fibrous sheath, in wliich, from the rigidity of its texture and 

 the similarity of colour, it became exceedingly difficult to follow them. The 

 larger and more distinct branches (5. 5. fig. 1. pi. 7.) enter respectively the roots 

 of the tentacles, which are lodged in the canals of the digitations, but those going 

 to the ophthahnic tentacles are somewhat larger than the others. There did 

 not appear to be any lateral connecting filaments between these nerves, probably 

 because there is no simultaneous action in the parts they supply, analogous to 

 that which is observed in the movements of the arms of the Poulp, &c. Below 

 these branches nimierous small nerves (6. 6. fig. 1. pi. 7.) are given off, which 

 enter the external labial processes, and penetrate in a similar manner the roots 

 of the tentacles lodged in these processes. The internal labial processes are, 

 however, supplied in a different manner : a larger ner\x (7. 7. fig. 1. pi. 7.) comes 

 off" near the ventral extremity of the ganghon, and after a course of half an inch 

 swells out into a flattened ganghon (8. 8. fig. 1. pi. 7.), from which munerous 

 tUaments extend into the substance of the process, and are continued into the 

 tentacles as in the preceding case: a branch (10. fig. 1. pi. 7.) also inchnes and 

 distributes filaments to the membranous laminae situated between the inferior 

 labial processes. A pair of ner\"es (11. pi. 7.) arises near the point of union of 

 the anterior subcesophageal gangUons, and passes forwards to be distributed to 

 the infundibulum and its muscles. 



From the brain itself, or general commissm-e, there are given off two larger 

 and two lesser pairs of nerves (12. pi. 7.) ; these supply the parts immediately 

 surrounding the mouth, the muscles of the jaws, and the tongue. 



From the ganglions composing the posterior collar numerous nerves of a 

 flattened form (13. pi. 7.) originate, which after a course of from half an inch to 

 an inch penetrate the muscles of the shell, without being produced to form a 

 ganglion stellatum (7. fig. 3. pi. 7.), as in the Cuttle-fish. It has previously been 

 observed that these nen^es penetrate the analogous muscles in the higher Ce- 

 phalopoda by a single trunk, which afterwards swells into a ganghon, and is 

 distributed to the thick muscular cloak of these genera. The visceral nerves, a 

 single pair (14. pi. 7.), which appear to combine the functions of the sympathetic 

 and par vagum, run down on each side of the vena cava, and at the termination 

 of that vein give off the branchial nerves (15. pi. 7.), and form on each side a 



