286 NEW YORK STATE MUSEUM 



aorta on the dorsal part of the stomach. It is subovate in form, 

 gradually enlarging from its posterior to its anterior extremity, 

 and is about four times as long as wide (4). 



From the outer anterior part of the principal ganglia proceeds 

 a stout nerve to the extremity of the superior tentacle (5). 

 Within the tentacle this nerve gives origin to a slender nerve 

 proceeding to the eye, the optic nerve. From a point closely 

 contiguous to the first mentioned nerve, but nearer to the anterior 

 margin, proceeds a nerve, smaller than the first, which near the 

 anterior extremity of the animal bifurcates, one branch going to 

 the mouth (7), the other to the ganglia at the extremity of the 

 inferior tentacle (6), From a point slightly nearer to the anter- 

 ior margin proceeds a nerve, which near the mouth bifurcates 

 and gives off nerves to the mouth and adjacent parts of the in- 

 tegument (7'). From the anterior lobe of the inner ganglia nerves 

 proceed to the muscles and integument of the superior pair of 

 tentacles (8). From the inner part of the principal ganglia pro- 

 ceed commissural cords, which unite with the anterior lobe of the 

 buccal ganglia (3'). 



The posterior lobes of the buccal ganglia are united by a short, 

 broad commissural cord (5"). 



From the anterior lobe of each buccal ganglion arise two 

 nerves, which proceed to the anterior part of the buccal body, 

 giving off numerous branches {9). 



From the inner part of each median lobe arises a nerve which 

 continues posteriorly alongside the esophagus [10) ; and from the 

 posterior lobe two nerves, which supply the posterior part of the 

 buccal body {11). 



The cephalic artery passes through the infra-esophageal gang- 

 lionic mass, the ganglia forming a ring, and in an uninjected 

 specimen might easily be mistaken for a large nerve. 



From the posterior part of the dorsal ganglia proceed five 

 nerves, three of which are of nearly equal diameter; the other two 

 are smaller. The one to the left is free for a short distance, then 

 buries itself in the substance of the retractor muscles, continuing 

 to the origin of the muscles in the muscular layer. 



