Key to species of Synelmis found in Brazilian waters

1. Lateral antennae located on anterior margin of prostomium................... Synelmis amoureuxi Salazar-Vallejo, 2003

- Lateral antennae located in the middle of prostomium........................................................ 2

2. Tentacular segment prominent; dorsal cirri longer in anterior chaetigers; notopodial spines from chaetiger 17–22................................................................................. Synelmis sotoi Salazar-Vallejo, 2003

- Tentacular segment short; all dorsal cirri similar in length to tentacular cirri; notopodial spines from chaetiger 10.................................................................................. Synelmis albini (Langerhans, 1881)