Orders of subclass3-PULMONATA

The subclass 3-Pulmonata has only two orders namely as follows.
Order 1:-BASOMMATOPHORA
  Order 2:-STYLOMMATOPHORA


Order 1:-BASOMMATOPHORA 
          1) They are found in marine water, freshwater and brackish
              water.
          2) They have delicate shell with a conical spire and large
               aperture.
         3) They have one pair of non-invaginable tentacles with the   
          eyes at their bases.
         4) The male and female gonopores are generally separate.
               Examples:- Siphonaria, Lymnaea, Planorbis

ventral surface of Siphonaria

Siphonaria in garden

Dorsal structure of Siphonaria

                                          

planorbis

Lymnaea

Lymnaea

Order2:-STYLOMMATOPHORA
       1) They are terrestrial pulmonates.
         2) They have shell with a conical spire, internal or absent.
         3) They have two pairs of invaginable or retractile tentacles
             with the eyes at the tips of the posterior pairs.
         4) They have male and female gonopores usually united.
             Examples:- Limax, Helix, Partula, Retinella.

limax

Partula

Retinella.