The platyscelis group of the carabid genus Agra Fabricius, an equatorially centered lineage, consists of 30 species that have a composite range extending from the isthmus of Panamá to French Guiana south into Brazil and Bolivia. The majority of species are found in the Amazon Basin. Structural features of both body and appendages are convergent with other carabid beetles that are known to dwell in ant nests, however, no life history of any Agra species is known. The following 12 specific taxa of the platyscelis group are described as new (type locality in parenthesis): A. tingo new species, (PERU, Huánuco, 13 km S Tingo Maria, Tambillo, Chico Canyon, 09°15′S, 76°23′W); A. biolat new species, (PERU, Madre de Dios, 30 air km SW Puerto Maldonado, Rio Tambopata Res., 12°50′S, 69°20′W); A. aeris new species, (PERU, Madre de Dios, BIOLAT Biodiversity Station, Pakitza, 11°56′S, 71°17′W); A. solimoes new species, (BRAZIL, Amazonas, Tefé (Ega), 3°22′S, 64°42′W); A. servatorum new species, (PERU, Loreto, 1km SW Boca del Rio Samiria, Vigilante Post No. 1, 04°40′S, 74°18′W; A. conhormigas new species, (PERU, Madre de Dios, 30 air km SW Puerto Maldonado, Rio Tambopata Res., 12°50′S, 69°20′W); A. lilu new species, (BRAZIL, Amazonas, Humaitá, 07°32′S 63°02′W); A. lindae new species, (PERU, Madre de Dios, 30 air km SW Puerto Maldonado, Rio Tambopata Res., 12°50′S, 69°20′W); A. rondonia new species, (BRAZIL, Rondonia, Ariquemes, 9°56′S, 63°03′W); A. nex new species, (BRAZIL, Amazonas, 2km N Itacoatiara-Manaus Highway, 11 km, W of Itacoatiara, Canadian Fathers' Pool, 03°08′S, 58°28′W); A. manu new species, (PERU, Madre de Dios, Manu Biosphere Res., Pakitza, 11°56′S, 71°17′W); A. dax new species, (PANAMA, Canal Zone, Barro Colorado Is., 09°10′N, 79°50′W). The females of A. iquitosana Erwin and A. sasquatch Erwin, and the male of A. varzeicola Erwin are described and illustrated for the first time.

A revised key and checklist are provided and distributions of all 33 species are dot-mapped. A general discussion for each of the new species, as well as for 12 additional species for which new locality records were found (A. klugii Brullé, A. limulus Erwin, A. varzeicola, A. iquitosana, A. tarapotana Erwin, A. titan Erwin, A. platyscelis (Chaudoir), A. caliga Erwin, A. yeti Erwin, A. semiviridis (Straneo), A. sasquatch Erwin, and A. azureipennis Erwin) is included. Remarks on systematics and biogeography based on the newly described specimens are provided.

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