320 j\Ir. C. T. Ilegan on the Fishes of ihe 



it ; scales of thoracic icj^ion considerably smaller than those 

 on the side of the body. Mouth moderate, moderately 

 protractile ; maxillary sliglitly exposed ; teeth of the outer 

 series small or moderate, in the upper jaw moderately in- 

 creasing in size anteriorly, in the lower with 4 or 5 anterior 

 teeth on each side distinctly enlarged. Dorsal XV-XVIl 

 8-1 :i. Anal VI-IX G-9. Dorsal and anal fins entirely 

 scalcless. Caudal slightly cmarginate, with pointed lobes. 



Three species from Mexico and Central America are allied 

 to C. macracanthus &c., but differ from all other members 

 of the genus in the scaleless dorsal and anal fins and in the 

 form of the caudal. 



43. Cichlosoma aureum. 



Heros aureus. Glintli. Cat. Fish. iv. p. 1292 (1862), and Trans. Zool. 



Soc. vi. 1869, p. 455, pi. Ixxiii. fi<r. 2; Jord. & Everm. Bull. U.S. 



Nat. Mus. xlvii. 1898, p. 15.:i3 ; Pellegv. Mem. Soc. Zool. France, 



xvi. 1903, p. 238 (1904). 

 Heros Selleri, Steind. DeukscLr. Ak. Wion, xxiii. 1864, p. 64, pi. iv. 



fig. 1. 

 Heros macidiphini'^, Steind. t. c. p. 69, pi. iv. fig. 2 ; Jord. & Everm. 



Bull. U.S. Nat. Mus. xlvii. 1898, p. 1530 ; Pellegr. t. c. p. 240. 

 Cicldasoma Helleri, Jord. & Everm. t. c. p. 1621 ; Pellegr. t. c. p. 220. 

 Thorichtlijis Helleri, 31eek, Zool. Pub. Columbian Mus. v. 1904, p. 223. 

 Thorichthi/s Elliot i, Meek, I. c. fig. 72. 



Depth of body 2-2? in the length, length of head 2§-3. 

 Snout straight, as long as postorbital part of head. Diameter 

 of eye 2|-3i in the length of head, interorbital width 3-3J. 

 Depth of praeorbital equal to the diameter of eye or less. 

 Maxillary not quite extending to below the eye; prsemaxillary 

 processes extending to above anterior ^ of eye; jaws equal 

 anteriorly ; fold of the lower lip continuous or not ; cheek 

 with 4-6 scries of scales ; 9 or 10 gill-rakers on the lower 

 part of anterior arch. Scales 29-32 J^, 2 or 3 between 

 lateral line and base of anterior rays of soft dorsal. Dorsal 

 XV-XVII 9-12, commencing above the opercular cleft, the 

 spines subequal from the sixth, the last about ^ tlie length 

 of head; soft fin, when laid back, extending to anterior .1 or 

 middle of caudal. Anal VII-VIII 7-8 (VI-IX 6-9). 

 Pectoral as long as the head, extending to above middle anal 

 spines ; ventral extending beyond origin of anal. Caudal 

 slightly emarginate with pointed lobes. Caudal peduncle a 

 little deeper than long. Olivaceous, Avitli 6 dark cross-bars, 

 the third bearing a blackish blotch on or below the lateral 

 line ; suboperculum usually blackish ; head and anterior part 



