gracilis, Tomeurus Eigenmann [C. H.] 1909:53 [Annals of the Carnegie Museum v. 6 (no. 1); ref. 1222] Mud Creek in Aruka River, Guyana. Holotype: FMNH 53541 [ex CM 1093]. Paratypes: BMNH 1911.10.31.537 (1); CAS 22774 [ex IU 12076] (3); FMNH 53542 [ex CM 1094] (1), 52722 [ex CM 1095] (1), 53541-42 (1, 1). Type catalog: Henn 1928:87 [ref. 12305], Ibarra & Stewart 1987:83 [ref. 12367] as 2 paratypes from 2 localities. •Valid as Tomeurus gracilis Eigenmann 1909 -- (Rosen & Bailey 1963:39 [ref. 7067], Keith et al. 2000:62 [ref. 24547], Ghedotti 2000:38 [ref. 27228], Lazara 2001:307 [ref. 25711], Lucinda in Reis et al. 2003:572 [ref. 27061], Lucinda & Reis 2005:37 [ref. 29205], Meyer 2015:358 [ref. 34698]). Current status: Valid as Tomeurus gracilis Eigenmann 1909. Poeciliidae: Tomeurinae. Distribution: Brazil, Guyana, Suriname and Venezuela. Habitat: freshwater.