258 INTRODUCTION. 



Pig. V. Genitalia. Same references as Fig. I. 

 Fig. VI. Animal with the penis and lower portion of the dart sac. 

 Fig. VII. Dental plate. 



Fig. VIII. Genitalia of H. suppressa, magnified seven diameters. 

 Same references as Fig. I. 



Figs. IX. — XI. H. concava. 



Fig. IX. Digestive apparatus. Same references as Fig. I. PL 

 XI. 

 Fig. X. Genitalia. Same references as Pig. VI. PI. IX., except 



1 1 , which is probably a dart sac ; 12. cloaca. 

 Pig. XI. Dental plate, much magnified. 



PLATE Xin. 



Pig. I. — III. SucciNEA. 



Pig. L Viscera dissected apart. 1. Buccal body; 2. stomach; 3. 

 intestine; 4. rectum; 5. anus; 6. salivary gland ; 7. ducts of do.; 8. 

 liver; 9. testicle; 10. epididymis ; 11 . accessory gland of do. ; 12. pros- 

 tate; 1.3. penis; 14. ovary; 15. oviduct; 16. genital bladder; 17. 

 pulmonary chamber ; 18. heart; 19. renal organ. 



Fig. II. Genitalia. Same references as Pig. VI. PI. IX. 



Pig. III. Dental plate, a. Natural size; b. magnified; 1. mus- 

 cle; 2. dental plate; 3. accessory plate. 



Fig. IV. Nerve centres of Helicina orbiculata, highly magnified. 

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

 ojsophageal ganglia ; 4. auditory vesicles. 



Pig. V. Spermatozoa from the epididymis, very highly magnified. 



PLATE XIV. 

 Glandina truncata. 



Pig. I. Animal deprived of its shell. 1. Turbinate mass of vis- 

 cera; 2. anterior third of the buccal body protruded as in eating; 3. 

 mouth; 4. generative aperture ; 5. suiDcrior tentacles ; 6. inferior ten- 

 tacles ; 7. external tentacles. 



Pig. II. Viscera dissected apart. 1. Buccal body; 2. oesophagus ; 

 2.* exit of do. ; 3. stomach; 4. intestine; 5. rectum; 6. anus; 7. sali- 

 vary gland; 8. ducts of do.; 9. liver; 10. hepatic duct; 11. testicle; 



12. epididymis ; 13. accessory gland of do. ; 12". vas deferens ; 14. pros- 

 tate; 15. penis; 16. retractor of do.; 17. ovary; 18. oviduct; 19. genital 

 bladder; 20. vagina; 21. cloaca; 22. pulmonary chamber; 23. pul- 



