Cellar Slug. 189 



formed by the inferior surface of the oesophagus with the 

 buccal mass just where it enters it, together with the duct 

 of the salivary gland. The ganglion is connected by a long 

 and delicate commissural cord with the supra-oesophageal 

 ganglion of its own side, and it gives off nerves to the buccal 

 mass, to the oesophagus, and to the duct of the salivary 

 gland. 



ff. Salivary gland. 



A. Buccal mass containing the ^ tongue.' 



i. Semper's organ ; a structure consisting of cells like those of a 

 salivary gland, but devoid of a duct, and very richly sup- 

 plied with nerves from the supra-oesophageal mass, and 

 supposed by its discoverer to be, possibly, an olfactory 

 organ. See Semper, ' Beitrage zur Anatomic und Physio- 

 logic der Pulmonaten,' in the Zeitschrift fiir Wissenschaft- 

 liche Zoologie, Bd. viii., 1857, p. ^66. It is large in Li- 

 maces, though small in the other air-breathing Gastero- 

 poda. 



J. Coecal projection at pyloric end of stomach. 



k. Liver, consisting of two main lobes opening each by a single 

 duct into the digestive tube along the line of the opening 

 of the stomach into the intestine. 



I. Intestine passing from pylorus to end close by the respiratory 

 inlet, but a little in front and above it. Its two fii'st convo- 

 lutions have been uncoiled in separating it from the liver 

 and reproductive apparatus, but as it approaches the dorsal 

 integument and shield it describes a curve like that of an 

 Italic S. In the first concavity of this curve we see the 

 stem of origin for the retractor muscles of the buccal mass 

 and labial tentacles, and at its opj^osite extremity we see a 

 straight coecum ^ pass off and extend nearly to the posterior 

 extremity of the body. 



m. Respiratory orifice, with the ' rectum' curving round it 

 to open a little above and anteriorly to it. To the 

 right of the rectum again is seen the duct of the renal 

 organ. 



n. Portion of dorsal integument, by making an incision imme- 

 diately to the right of which the shell would be found. 

 Internally to it we see the respiratory sac, with the rami- 



