POLYGYRA ALBOLABRIS AND LIMAX MAXIMUS 285 



The fifth pair are situated below the fourth pair. Their inner 

 margins are nearly in contact. 



The large cephalic artery passes through the ganglionic mass, 

 bounded above and below by the third and fifth pair of ganglia, 

 and laterally by the fourth pair. 



The sixth pair are below the fourth and fifth pair of ganglia, 

 and when the ganglionic mass is viewed from above are almost 

 hidden from sight. 



The ganglionic masses are connected by two pairs of commis- 

 sural cords, the upper ones of which proceed from the second pair 

 of the supra-esophageal ganglia, and continue to the under part 

 of the fourth pair of infra-esophageal ganglia. The inferior pair 

 of cords proceed from the posterolateral part of the lower lobe of 

 the inner, or third pair of supra-esophageal ganglia, and continue 

 to the lower part of the sixth pair of infra-esophageal ganglia. 



Two smaller ganglia are situated near the dorsal surface of the 

 posterior part of the buccal body, one on each side of the esoph- 

 agus, just as it leaves the buccal body. They are comparatively 

 small, a little less than three times as long as wide, and are 

 divided into three nearly equal lobes, (3) the anterior one being 

 broader and shorter than the other two, which are nearly round. 



The two ganglia are connected by a strong commissural cord 

 proceeding from the posterior lobes. 



The buccal ganglia are connected with the cerebral ganglia by 

 two commissural cords, which proceed from the under surface of 

 the inner pair of cerebral ganglia, to the outer and under part 

 of the anterior lobes of the buccal ganglia. 



There are ganglionic swellings in the extremities of both the 

 superior and inferior tentacles. That in each superior tentacle is 

 digitate in form, the palm being exaggerated in size and the 

 fingers short. From each of these processes, or fingers, numerous 

 fibers proceed to the thin integument at tlie end of the toiilacle. 

 The ganglia of the inferior tentacles are pyriform, the largest end 

 being nearest to the extremity of the tentacle, and giving off 

 numerous fibers to the extremity of the tentacle. 



A small ganglion is situated near the first branching of tli • 



