R. sibiricus, [109]

Raniformes, [139], [140]

Raninae, [139], [237], [238] f.;

distribution, [239]

Rappia, [241]

Rat Snake, [611], [612]

Rattle of Rattle-Snake, [644]

Rattle-Snake, [648] f., [648], [650]

Reduction of limbs, in Urodela, [16];

in Lacertilia, [497]