Simo - Steg
- Simophis
- Simophis rhinostoma
- Simophis rohdei
- Simoselaps
- Simoselaps anomalus
- Simoselaps australis
- Simoselaps bertholdi
- Simoselaps fasciolatus
- Simoselaps incinctus
- Simoselaps littoralis
- Simoselaps minimus
- Simoselaps semifasciatus
- Simoselaps warro
- Sinonatrix
- Sinonatrix aequifasciata
- Sinonatrix annularis
- Sinonatrix bellula
- Sinonatrix dunni
- Sinonatrix percarinata
- Sinonatrix trianguligera
- Siphlophis
- Siphlophis cervinus
- Siphlophis cinereus
- Siphlophis leucocephalus
- Siphlophis longicaudatus
- Siphlophis pulcher
- Siphlophis worontzowi
- Siphonops
- Siphonops annulatus
- Siphonops confusionis
- Siphonops hardyi
- Siphonops insulanus
- Siphonops leucoderus
- Siphonops paulensis
- Siren
- Siren intermedia
- Siren lacertina
- Sirenidae
- Sistrurus
- Sistrurus catenatus
