WATSON : ANATOMY OF HELICARION. ll^ 



EXPLANATION OF PLATE III. 



Helicarion gomesianus (Morelet) ; Pemba, Rhodesia. 

 Fig. 



1. Animal and shell (preserved in spirit), seen from the right side. x 2. 



2. Animal and shell (preserved in spirit), seen from the left side, x 2. 



3. Shell, seen from the front. x '2. 



4. Central nervous system, seen from above. x 8. 



5. Pedal ganglia, seen from below. x 8. 



6. Alimentary canal, seen from above. x 4. 



7. Jaw, seen from the front. x 12. 



8. Representative teeth from the radula, seen from above, x 200. 



9. Free retractor muscles, seen from above, x 4. 



10. Reproductive system, seen from above, x 6. 



11. Posterior half of penis, split open and seen from within, x 8. 



12. Calcareous granules from the epiphallus. x 800. 



13. Anterior end of spermatozoon. x 800. 



EXPLANATION OF PLATE IV. 

 Helicarion cryptophallus, n.sp. ; British East Africa. 

 Fig. 



1. Animal and shell (preserved in spirit), seen from the right side, x 2. 



2. Animal and shell (preserved in spirit), seen from the left side, x 2. 



3. Shell, seen from the front. x 2. 



4. Shell, seen from the beneath, x 2. 



5. Spire of shell, seen from above. x 6'5. 



6. Animal without its shell, seen from above. x 3. 



7. Roof of mantle cavity, seen from within, showing respiratory and 



excretory organs. x 4. 



8. Anterior end of spermatozoon, x 800. 



9 Reproductive system, seen from above, x G. 



10 Calcareous granules from the epiphallus. x 800. 



11. Free retractor muscles, seen from above. x 4. 



12. Contents of penis-sheath, with posterior end of penis split open (to show 



penis-papilla, etc.). x 8. 

 13 Jaw, seen from the front, x 12. 



14. Representative teeth from the radula, seen from above. X 200. 



