natatory

Its exact position likewise varies, for it arises either between the first or second pairs of natatory legs.

In this fig. 3, it may be observed that the natatory legs and caudal appendages of the pupa have not as yet been moulted.

Many female parasitic crustaceans have lost their natatory legs.

It is now understood that they are Euthyneurous Gastropods adapted to natatory locomotion and pelagic life.