VII 



MOLLUSGASYSTEMA TIC REVIEW 



23 



Km. :. Spirula prototypes, riicht aspect (after Chun and Owen), 

 from Leuckart ami Nitsche, /ool. ll'iniiltiifrhi. Both portions of the 

 shell are visible, the inner portion seen through the mantle. The eye 

 should be placed more anteriorly on the " head" (Kopllus-o. 





Fin. 34. Loligo vulgaris (alter D'Orbigny). .1, Dorsal (physiologically ventral) view; 7;, 

 anterior (physiologically dorsal) view, of the five pairs of arms, the fourth are seen to be 

 developed as lon^ prehensile tentacles ; the eyes, the cd.ue of the mantle, the lins, and the 

 ohromatophores in the skin are depicted. 



