H/iJJX. 267 



If the dorsal surface of the body be now cut open by a 



median incision, the alimentary, reproductive and nervous 



AU tarv ^ystems are all exposed, and may be easily dis- 



niary. ^^^^.^^ ^^^.^ j|- ^.j^^ alimentary organs be moved 



over to the left and the reproductive to the right, the 



appearance of Fig. J87 is produced. 



The mouth leads into a large muscular buccal mass. It 

 contains the odontophore (or radula), an important molluscan 



Fig. 188.— The Nervous System of the Snail. 



Removed entire, and viewed from the dorsal side. (After Howes,) 



Buccal Nerve 



Cerebral 



Ganglion. 



Verve to 



Otocyst. _ 



Pedal Ganglion. 



Otocyst. 



3rgan. The odontophore is a long ribbon^^bearing in- 

 numerable rows of little chitinous teeth. ItJ grows [from 

 1 root posteriorly as it is worn away anteriorly, and lies over 

 1 buccal cartilage moved by muscles. The snail employs it 

 like a rasping tongue. On the dorsal side of the buccal 

 mass, just over the odontophore, open a pair of salivary 

 inds leading from salivary glands covering the stomach. 

 esophagus leads from the posterior ^nd of the buccal 



