EIGENMANN: the freshwater fishes of BRITISH GUIANA 485 



Dorsal spines low, becoming higher toward the last, which is a little less than 

 half the length of the head; caudal rounded, soft dorsal and anal sometimes pro- 

 longed to the end of the caudal; pectoral as long as or longer than the head, reach- 

 ing the soft part of the anal; ventrals sometimes reaching the rayed part of the 

 anal. 



A dark streak from the symphysis to the lower border of the preopercle, 

 another one from the edge of the preorbital parallel with the one below it, both 

 faint or absent in the young; a black spot on the middle of the sides, sometimes 

 an obscure stripe from the upper angle of the gill-opening to the end of the soft 

 dorsal; sometimes each scale of the sides with a light base and dark central spot; 

 vertical fins with oblique or transverse hyaline bars. 



AcAROPSis Steindachner. 

 Acaropsis Steindachner, "Chromiden Amazonenstromes," 1875, 80. 



Type, Acara nassa Meckel. 



With the characters of JEquidens, but the mouth large, the premaxillaries 

 very protractile; end of maxillary exposed, not slipping under the premaxillary. 



328. Acaropsis nassa (Meckel). 



Acara nassa Meckel, Ann. Wiener Mus., M, 1840, 353 (Rio Guapore). — Muller 

 and Troschel, in Schomburgk, Reisen, III, 1848, 624 (Lake Tapacuma). — 

 GtJNTHER, Catalogue, IV, 1862, 281 (River Cupai). — Vaillant, Nouv. Arch. 

 Mus. d'Mist. Nat., (4), II, 1900, 125 (Carsevenne). 



Acara (Acaropsis) nassa Steindachner, "Chromiden Amazonenstromes," 1875, 

 81, pi. 2 (Gurupa; Montalegre; Tonantins; Villa Bella; Santarem; Teffe; 

 Coary; Serpa; Obidos; Curupira; Ueranduba; Tapajos; Rio Negro; Xingu; 

 Myutay; Madeira; Guapore; Lakes Alexo, Maximo, Jose Assu, Saraca; 

 Manacapuru).— Pellegrin, Bull. Mus. d'Mist. Nat., VIII, 1902, 182 (San- 

 tarem; Manaos; Teffe; Tonantins). 



Acaropsis nassa Eigenmann and Bray, Ann. N. Y. Acad. Sci., VII, 1894, 613. — - 

 Pellegrin, "Cichlides," 144, in Mem. Soc. Zool. France, XVI, 1903, 180 

 (Orinoco; French Guiana; Manaos; Tonantins). — Regan, Ann. and Mag. 

 Nat. Mist., (7), XV, 1905, 345 (Rio Cupai; Demerara; Teffe; Tonantins).— 

 VON Ihering, Rev. Mus. Paulista, VII, 1907, 307. — Eigenmann, Repts. 

 Princeton Univ. Exp. Patagonia, III, 1910, 470. 



Acara cognatus Meckel, Ann. Wiener Mus., II, 1840, 356 (Barra do Rio 

 Negro). 



