EIGENMANN: the freshwater fishes of BRITISH GUIANA 501 



Head 3+ ; depth 2.25-3; D. XII-XIV,11 or 12; A. 111,7 or 8; lateral line 

 18-19 + 13-16; scales 29-30 in a median series; eye 3.5 in the head, 1.3 in the 

 preorbital, 1 in the interorl^ital in the largest; eye in posterior half of the head in 

 the young. 



Dorsal profile steep, the l^ack arched; ventral profile Ixit slightly arched; 

 maxillary-premaxillary border 3.5 in the head; maxillary reaching a little beyond 

 the posterior nares, which are half-way between the tip of the snout and the eye. 

 Lower lip with a frenum; depth of caudal peduncle 1.25 in its length. Gill-rakers 

 1 1 , the upper two at the base of the lobe. 



Cheeks with about six series of scales; preopercle naked; one scale between 

 the lateral line and the dorsal. Base of caudal scaled, fins otherwise naked. 



Dorsal spines subequal from the third, the last a little more than half the length 

 of the head; dorsal sometimes prolonged beyond the caudal; caudal emarginate, 

 its outer rays prolonged ; pectoral longer than the head. 



A narrow dark bar from the nape through the eye to the angle of the preopercle; 

 a black spot near the middle of the sides; a black spot on the anterior dorsal spines; 

 dorsal, caudal, and anal with hyaline spots. 



BiOTODOMA Eigenmann and Kennedy. 

 Mesops GtJNTHER, Catalogue, IV, 1862, 311 (cupido), preoccui^ied. 

 Biotodoma Eigenmann and Kennedy, Proc. Acad. Nat. Sci. Phila., 1903, 533. 



Type, Geophagus cupido Meckel . 



Upper gill-arch with a downward projecting lobe, carrying the gill-rakers at 

 its margin; upper lateral line well separated from the dorsal; lateral line not forked 

 on the caudal; preorbital about equal to the eye in the adult. 



340. Biotodoma cupido (Heckel). 



Geophagus cupido Heckel, Ann. Wiener Mus., II, 1840, 399 (Rio Negro; Rio 



Guapore). — Cope, Proc. Am. Philos. Soc, XVII, 1878, 697 (Peruvian Amazon). 



— Pellegrin, "Cichlides," 153, in Mem. Soc. Zool. France, XVI, 1903, 189 



(Obidos; Manaos; Tonantins). — Regan, Ann. and Mag. Nat. Hist., (7), XVII, 



1906, 54 (Essequibo; Tonantins). — yon Ihering, Rev. Mus. Paulista, VII, 



1907, 317. 



Mesops cupido GtJNTHER, Catalogue, IV, 1862, 311 (Rio Negro; Guapore). 



Geophagus (Mesops) cupido Steindachner, "Chromiden Amazonenstromes," 1875, 

 47 (Amazon, near Teffe; Coary; Cudajas; Lake Hyanuary; Rio Negro; Gua- 

 pore; Iga; Hyiitay; Sambaia; Jatuarana). — Eigenmann and Eigenmann, 

 Proc. U. S. Nat. Mus., XIV, 1891, 70 (name only).— Pellegrin, Bull. Mus. 



