HELIX, 267 
‘If the dorsal surface of the body be now cut open by a 
median incision, the alimentary, reproductive and nervous 
systems are all exposed, and may be easily dis- 
sected out. If the alimentary organs be moved 
over to the left and the reproductive to the right, the 
appearance of Fig. 187 is produced. 
The mouth leads into a large muscular buccal mass. It 
contains the odontophore (or radula), an important molluscan 
Alimentary. 
Fig. 188.—THE NERVOUS SYSTEM OF THE SNAIL. 
Removed entire, and viewed from the dorsal side. (After Howes.) 
Buccal Nerve 
Cerebral 
Ganglion. ——~ 
Nerve to 
Otocyst. __ 
Pleural. 
Visceral. ~ a i Otocyst. 
organ. ‘The odontophore is a long ribbon bearing in- 
numerable rows of little chitinous teeth. It grows from 
a root posteriorly as it is worn away anteriorly, and lies over 
a 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 
ducts leading from salivary glands covering the stomach. 
The esophagus leads from the posterior end of the buccal 
