254 INTRODUCTION. 



13. ovary; 14. oviduct; 15. genital bladder; 16. pulmonaiy chamber ; 

 17. heart; 18. renal orf^^an ; 19. renal duct; 20. pulmonary aperture. 



Fig. III. Dental plate, magnilied. 1. Muscle ; 2. the plate. 



Fig. IV. Penis laid open. 1. Penis; 2. thick longitudinal fold; 

 3. vas deferens ; 4. retractor of penis. 



Fig. V. Spermatozoa, highly magnified. 



Fig. VI. Digestive apparatus of H. perspectiva. 1. Buccal body ; 



2. retractor of buccal body ; 3. oesophagus; 4. stomach; 5. intestine; 



6. salivary gland; 7. ducts of do. ; 8. hepatic ducts. 



Fig VII. Genitalia. 1. Testicle; 2. epididymis; 3. accessory 

 gland of do.; 4. prostate ; 5. penis ; 6. retractor of do.; 7. ovary; 8. 

 oviduct; 9. genital bladder; 10. cloaca; 11. right superior tentacle. 



Fig. VIII. Dissection of H. palliata. 1. Buccal body ; 2. stomach ; 



3. intestine; 4. rectum; 5. anus; 6. salivary gland ; 7. liver; 8. epidi- 

 dymis; 8.* vas deferens ; 9. accessory gland of do. ; 10. prostate; 11. 

 penis; 12. retractor of do. ; 13. ovary; 14. oviduct; 15. genital blad- 

 der ; 16. retractor of buccal body ; 17. pulmonary chamber ; 18. heart ; 

 19. renal organ; 20. supra-cesophageal ganglia. 



PLATE VIII. 

 Figs. I. — VI. Helix multilineata. 



Fig. I. Digestive apparatus. 1. Buccal body; 2. retractor of do.; 

 3. lingual pouch ; 4. stomach ; 5. intestine ; 6. salivary gland ; 7. 

 hepatic duct. 



Fig. II. Genitalia. 1. Testicle; 2. epididymis; 2.* vas deferens ; 

 3. accessory gland of epididymis; 4. prostate; 5. penis; 6. prepuce; 



7. retractor of penis ; 8. ovary; 9. oviduct; 10. genital bladder; 11. 

 vagina; 12. cloaca; 13. right superior tentacle. 



Fig. III. Penis (1) laid open to exhibit the papillary structure on 

 its inner surface ; 2. prepuce ; 3. vas deferens ; 4, 5. neck of oviduct 

 and vagina laid open; 6. bladder; 7. orifice of bladder. 



Fig. IV. Portion of the inner surface of the penis, magnified two 

 diameters. 



Fig. V. Spermatozoa, highly magnified. 



Fig. VI. Spermatozoa in coil. 



Figs VII. — X. H. solitaria. 



Fig. VII. Digestive apparatus. Same references as Fig. I. 



Fig. VIII. Genitalia. 1. Testicle ; 2. epididymis ; 2.* vas deferens ; 

 3. accessory gland of do. ; 4. pi'ostate ; 5. penis; 6. retractor of do. ; 

 7. ovary; 8. oviduct; 9. bladder; 10. cloaca. 



