Characteristics of order2 –Mesogastropoda of sub class PROSOBRANCHIA

1)    They are the Prosobranchia with siphon, penis  and 
        non –calcified Operculum.

2)    They have radula of taenioglossare type with 7 teeth   
        in each row.

3)    They have one monopectinate gill.

4)    They have heart with one auricle.

5)    They have one ospharadium and  nephridium.

6)    They have nervous system concentrated without pedal cords.

Examples:-Viviparus, Ampullarius, Pila, Valvalata, Truncatella, Littorina, Hydrobia, Jonthina,Cypraea.

Viviparus

Ampullarius 

Ampullarius gigas

   
        

Cypraea

Hydrobia

Littorina

Littorina

Cypraea.

Cypraea.