Which of the following is absent in a $Salamander$?

$S$ - Statement: $Capelle$ classified frogs and $Ichthyophis$ into $Amphibia$.
$R$ - Reason: Frogs and $Ichthyophis$ possess a three-chambered heart.

The common name of $Necturus$ is

The $Axolotl$ larva belongs to the order:

Frogs and toads are included in the order .......

Statement $X$: The skin of amphibians acts as a respiratory organ.
Statement $Y$: Amphibians lack an exoskeleton and have moist skin.