Torsion and Detorsion in Gastropoda 

Topics Covered
1: Evolution of torsion, Progastropods, Whorls,Planispiral, Exogastrically, Endogastric, Torsion, Conispiral,
2: Changes in torsion, Mantle, Mantle cavity, Nephridiopores, Hypobranchial, Osphradia, Torted, Untorted, Detorted, Streptoneury, Euthyneury,
3: Advantages of torsion,
4: Evolutionary significance of torsion,
5: Detorsion, pallial complex, Opisthobranchia, Pulmonata,