HANDLES : ANATOMY OF TtJKRITELLA COMMUNIS. 



65 



EXPLANATION OF PLATE VI. 



Fig. 1. Turritella communis, Risso. Side view of the head. 



,, 2. . General dissection of a female. 



,, 3. . Nervous system seen from above. 



,, 4. . Nervous system seen from right side. 



,, 5. . Transverse section through the mantle - cavity of 



a male, x 20. 



,, 6. . Transverse section through the end of mantle-cavity 



and beginning of visceral mass, x 22. 

 ,, 7. Radula of Turritella australis. 



