348 HANDBOOK OF INVERTEBRATE ZOOLOGY. 



the nerves (Fig. 181, a, a), which pass to the ganglia 

 stellata. 



i. On each side of the oesophagus, where it passes into 

 the ventral surface of the liver, is a delicate, transparent, 

 hepatic duct (Fig. 180, jf^), which may be traced into the 

 spleen [g), and through this organ to the stomach. 



j. Raise up the stomach, and notice below it, in a cap- 

 sule of its own, the testis or ovary, according to the sex 

 of the specimen. A large, compact, white body on the 

 median line, and on the left of it notice the accessory 

 reproductive organs. 



V. Divide the head vertically, with a razor, by a single 

 cut through it, along the median line. In the section thus 

 made notice : 



a. The opening of the mouth, between the bases of the 

 arms. 



b. The two horny jaws, one on the dorsal side of the 

 mouth, and one on the ventral side. The former (Fig. 

 185,/*), is smaller than the ventral one, d, into which it 

 shuts. 



c. The nearly spherical, muscular, buccal body. 



1. The cavity of the oesophagus (Fig. 185, c), running 

 through it, near its dorsal surface. 



2. The lingual ribbon (Fig. 185, ^'), lying upon the 

 floor of the oesophagus. 



d. Behind the buccal body the small oesophagus, (c), 

 runs backwards through the head and neck to the body, 

 where it lies dorsal to the liver, as already noticed. 



e. In the section notice the cartilaorinous rino; or cranium 

 which surrounds the oesophagus, in the posterior portion 

 of the head. 



f. The ganglia of the nervous system, which are ar- 

 ranged in a ring around the oesophagus, within and ante- 

 rior to the cranium. 



