260 INTRODUCTION. 



oesophageal ganglia; 2. sub-oesophageal ganglia; 3. stomato-gastric 

 ganglia; 4. nerve to the upper lip; 5. to the integument of the superior 

 tentaeulse; 6. to the lateral lips ; 7. supra-cesophageal, stomato-gastric 

 ganglionic commissure; 8. superior tentacular nerve; 9. an accessory 

 branch; 10. nerve to the inferior and external tentaculie; 11. gan- 

 glionic enlargement of do.; 12. inferior tentacular nerve ; 13. external 

 tentacular nerves; 14. nerves to the buccal body; 15. to oesophagus 

 and stomach; 16. to salivary ducts and gland; 17. supra-oesophageal, 

 sub-cesophageal, ganglionic commissures; 18. nerves to podal disk; 

 19. nerves to collar and pulmonary chamber; 20. to retractor of buc- 

 cal body; 21. follows course of aorta, and supplies the oviduct, ovary, 

 testicle, etc. ; 22. supplies integument, collar, pulmonary chamber, and 

 retractor muscles, at origin ; 23. to penis; 24. to cloaca and integu- 

 ment in vicinity ; 25. numerous branches to integument on each side, 

 and podal disk ; 26. to retractor muscles ; 27. to tail and podal disk; 

 28. large branch to integument on each side. 



Fig, II. Supra-CESophageal and stomato-gastric ganglia of Helix 

 albolabris. 1. Supra-oesophageal ganglia; 2. stomato-gastric ganglia. 

 3. supra-oesophageal, sub-oesophageal, ganglionic commissures; 4. su- 

 pra-oesophageal, stomato-gastric, ganglionic commissures; 5. superior 

 tentacular nerve; 6. inferior tentacular do. ; 7. to commencement of 

 olfactory sinus ; 8. inferior part of mouth and buccal body; 9. to inte- 

 gument of lips; 10. integument at side of mouth, and generative aper- 

 ture on the right side; 11. recurrent branch to superior tentacular 

 muscle; 12. to retractor of podal disk; 13. to buccal body; 14. to 

 oesophagus; 15. to salivary glands. 



