

A. OUTER SHELL OF MUSSEL 



B. VIEW OF MANTLE AFTER REMOVAL OF LEFT VALVE 



Many of the organs named in C are here visible through the semi-transparent mantle. 



C. EXTERNAL VIEW OF ORGANS AFTER REMOVAL OF LEFT HALF OF MANTLE 



i. FOOT. 2. MANTLE. 7. INHALANT SIPHON. 12. ANTERIOR RETRACTOR MUSCLE. 



3. OUTER GILL. 8. ANTERIOR ADDUCTOR MUSCLE. 13. POSTERIOR RETRACTOR MUSCLE. 



4. INNER GILL. 9. POSTERIOR ADDUCTOR MUSCLE. 14. 14. LESSER RETRACTOR MUSCLES. 



5. LABIAL PALPS. 10. PERICARDIUM. 15. PROTRACTOR PEDIS MUSCLE. 



6. EXHALANT SIPHON. ii. KEBER'S ORGAN. 16. MOUTH. 



D. GENERAL VIEW OF INTERNAL ORGANS 



1. FOOT. 



2. ANTERIOR ADDUCTOR MUSCLE. 



3. POSTERIOR ADDUCTOR MUSCLE. 



4. PERICARDIUM. 



5. 5. NEPHRIDIUM. 



6. AORTA. 



7. VENTRICLE. 



8. 8. INTESTINES. 9. RECTUM. 



10. ANUS. 



11. MOUTH. 



12. GILLS. 



13. STOMACH. 



14. LIVER. 



15. AURICLE. 



16. 16. GENITAL GLAND. 



17. NERVE COMMISSURE. 



18. CEREBRO-PLEURAL GANGLION. 



19. PEDAL GANGLION. 



20. VISCERAL GANGLION. 



21. POSTERIOR RETRACTOR MUSCLE. 



22. RENO-PERICARDIAL OPENING. 



23. OPENING OF NEPHRIDIUM. 



24. OPENING OP GENITAL GLAND. 



25. SIPHON. 



E. INTERIOR OF SHELL, SHOWING ATTACHMENTS OF FOLLOWING MUSCLES 



1. ANTERIOR ADDUCTOR. 4. POSTERIOR RETRACTOR. 6 and 7. ANTERIOR AND POSTERIOR LESSER RETRACTORS. 



2. POSTERIOR ADDUCTOR. 5. PALLIAL MUSCLES. 8. PROTRACTOR PEDIS. 



3. ANTERIOR RETRACTOR. 



