An analysis of the genus Stenomacra Stal with description of four new species, and some taxonomic rearrangements (Hemiptera : Heteroptera; Largidae).

Four new species of Stenomacra Stal from Costa Pica, Ecuador, and Brazil are described and illustrated. Stenomacra cliens (Stal), Stenomacra gracilis Schmidt, and Stenomacra marginella var. mexicana Schmidt are synonymized under Stenomacra marginella (Herrich-Schaeffer); Theraneis ferruginea Mayr is transferred to the genus Stenomacra and synonymized under Stenomacra scapha (Perty); Theraneis dissimilis Distant is transferred to the genus Stenomacra, resulting on the new combination Stenomacra dissimilis (Distant). New distributional data are included for each species. A key to the known species of Stenomacra is also given