ANATOMY OF ACLESIA FREERI. 85 



the case. The buccal ganglia are comparatively large. They 

 give origin to the stomatogastric nerves, as well as to those 

 which pass to the muscles of the buccal mass and to the salivary 

 glands. 



Each rhinophoral nerve ends in a small ganglion, lying at the 

 base of the inrolled, sensory surface of the rhinophore, from 

 which a number of fine nerves pass to all parts of the sensory 

 epithelium. There is no apparent tentacular ganglion, the ten- 

 tacular nerve ending in a network of fine branches under the 

 inrolled surface of the tentacle. The nerve of the oral lobe 

 ends similarly. Several nerves spring from each pleural gang- 

 lion and pass to the lateral and dorsal walls of the anterior half 

 of the body. A large nerve from each pedal ganglion passes 

 backward from along the junction of the foot and wall of the 

 body to the end of the tail. Branches pass from it to the 

 parapodia and the posterior half of the foot. Other nerves, 

 arising from the pedal ganglia, innervate the parapodia (fig. 33, 

 Plate VI, 14 and 15) and the anterior half of the foot (37). 

 A small, much-branched nerve passes from the right pedal gang- 

 lion to the penis, its muscles, and the body wall in its immediate 

 neighborhood. 



A large genital nerve extends from the visceral ganghon to a 

 small genital ganglion. From it some small nerves enter the in- 

 tegument around the vulva, while the principal nerve runs along 

 the sperm-oviduct until it reaches the point where the herma- 

 phrodite duct crosses the oviduct, traversing several small 

 ganglia on the way. At this point is a larger ganglion from 

 which the principal nerves of the albumen and hermaphrodite 

 glands arise. 



A much smaller nerve which arises from the left side of 

 the visceral ganglion (fig. 33, Plate VI, 23) runs, without any 

 branches, along the right side of the body to the rectum, where 

 it enters a small rectal ganglion ; from this a nerve passes along 

 the rectum toward the intestine. A third nerve, also very fine, 

 arises from the right side of the visceral ganglion (fig. 33, 

 Plate VI, 26), and runs directly backward; this was traced to 

 the duct of the spermatheca and to the pericardial wall. The 

 parietal ganglion gives rise to a single, large nerve which passes 

 to the osphradial ganglion (fig. 33, Plate VI, 27) ; the branchial 

 nerve arises from this and passes into the base of the gill. 



In life, the individual ganglia or groups of nerve cells are 

 vivid orange in color, and a better idea of their arrangement 

 can be obtained in fresh than in preserved specimens. The 



