NERVOUS SYSTEM. 1?09 



observed in this animal at the sides of the oesophagus (*) and 

 a transverse nervous band (,) connecting them, and encom- 

 passing that passage. From this nervous oesophageal ring 

 (?,) the two optic nerves pass laterally to the eyes (/,/,) and 



FIG. 89. 



the tentacular branches pass upwards and forwards to the 

 long slender tentacula (89. e, e.) Numerous branches ex- 

 tend downwards and laterally, to ramify on the muscular 

 parietes of the abdomen, and two principal trunks (k, k,) ex- 



PART II. p 



