398 FISHES OF WESTERN SOUTH AMERICA 
Chromys acara Castelnau, 1855, Anim. Amér. Sud, Poiss., 17, pl. ix, fig. 1. 
Heros (Heros) insignis Heckel, 1840, Ann. Wiener Mus., IH, 379. 
Mesonauta insignis Giinther, 1862, Cat. Fish. Brit. Mus., IV, 300; 
Pellegrin, 1902, Bull. Mus. Hist. Nat., VITI, 182. 
Cichlasoma insigne Pellegrin, 1903 (1904), Mém. Soc. Zool. France, XVI, 221. 
Uarus insignis Cope, 1871, Proc. Acad. Nat. Sci. Phila., XXII, 253, Rio Ambyiacu. 
Brazilian and Peruvian Amazons, Guiana, Paraguay 
17778, 10, 69-101 mm., Yarinacocha, Allen, August, 1920. 
Genus 207: ACARICHTHYS Eigenmann 
Acarichthys Eigenmann, 1912, Mem. Carnegie Mus., V, 500. 
Type: Acara heckelii Miller and Troschel 
British Guiana, Brazilian and Peruvian Amazons 
A genus of a form intermediate between Mquidens and Geophagus, with a 
feeble development of the dorsal lobe of the first gill-arch, and its small number of 
rakers, about two; mouth small and feebly protractile; caudal emarginate, its base 
scaled; eye posterior on head. 
513. ACARICHTHYS HECKELII (Miiller and Troschel) 
Acara heckelti Miller and Troschel, 1848, in Schomburgk, Reisen, IIT, 624; 
Giinther, 1862, Cat. Fish. Brit. Mus., IV, 279. 
Acarichthys heckeli Eigenmann, 1912, Mem. Carnegie Mus., V, 500. 
Geophagus thayeri Steindachner, 1875, Sitzb. KIX. Akad. Wiss. Wien, LX XI, 48, pl. iii, fig. 2; 
Pellegrin, 1902, Bull. Mus. Hist. Nat., VIII, 182, Tabatinga; 
Pellegrin, 1903 (1904), Mém. Soc. Zool. France, XVI, 189. 
Acara subocularis Cope, 1878, Proc. Amer. Phil. Soc., XVII, 696, Peruvian Amazon. 
Peruvian Amazon to the Guianas 
Genus 208: BIOTODOMA Eigenmann and Kennedy 
Mesops Ginther, 1862, Cat. Fish. Brit. Mus., IV, 311, preoccupied. 
Geophagus (Mesops) Steindachner, 1875, Sitzb. KKK. Akad. Wiss. Wien, LX.XT, 47. 
Geophagus (part) Pellegrin, 1903 (1904), Mém. Soc. Zool. France, XVI, 189. 
Biotodoma Eigenmann and Kennedy, 1903, Proc. Acad. Nat. Sei. Phila., LV, 533; 
Eigenmann, 1912, Mem. Carnegie Mus., V, 501. 
Type: Geophagus cupido Heckel 
Amazons, Guiana, Rio Guaporé 
With a downward-projecting lobe on the upper gill-arch, the gill-rakers along 
its border; upper lateral line well separated from the dorsal fin; lateral line not 
forked on the caudal fin; preorbital space about equal to the eye in the adult fish. 
