440 Mr. C. T. Regan on the Fishes of the 



15-16, the spines subequal from the fifth or sixth, the last 



the length of head, the soft fin scaly at the base. Anal 

 VIII-IX (X 12-13) 14 (15-16). Tectoral a little longer 

 than the head. Caudal rounded. Caudal peduncle ^-l as 

 long as deep. Brownish, with a broad blackish lateral band, 

 a blackish spot behind the eye and another on the upper 

 part of the base of caudal. 

 R. Amazon. 



1. (145 mm.) txT^s oi U. obscurwn. K. Cupai. 



2. (215 mm.) ' L. Saraca. Prof. A. Agassiz. 



3. (198 mm.) Tetfe. Paris Museum. 



Sy'MPHYSODON. 



Sympki/sodon, Heck. Ann. Mus. Wien, ii. 1840, p. 332; Giinth. Cat. 

 Fish. iv. p. 316 (1862) ; Steind. Sitzb. Ak. Wien, Ixxi. 1875, p. 106 ; 

 Eigenra. & Brav, Ann. Ac. N. York, vii. IBO-l, p. 623 ; Pellegr. 

 Mem. Soc. Zool." France, xvi. 1903, p. 249 (1904). 



Closely allied to Cichlosoma, especially to C severum, 

 differing in having the teeth confined to the anterior part of 

 each jaw and in the structure of the fins, the dorsal having 

 VIII-IX 28-31 rays and the anal VII-IX 26-31. The 

 body is nearly circular in form, compressed ; the scales are 

 rather small, those of the lateral line being larger than the 

 rest. 



A single species from the Amazon, 



Symphysodon discus. 



Symphysodo^i discus, Heck. Ann. Mus. Wien, ii. 1840, p. 333 ; Giintb. 

 Cat. Fish. iv. p. 316 (1862) ; Steind. Sitzb. Ak. Wien, Ixxi. 1875, 

 p. 106 ; Pellegr. M6m. Soc. Zool. France, xvi. 1903, p. 250 (1904). 



Depth of body 1-1^ in the length, length of head 3f-3f . 

 Snout as long as postorbital part of head. Diameter of eye 

 3-3^ in the length of head, interorbital width 2-22. Depth 

 of prseorbital 1-1 ^ the diameter of eye. Mouth small, 

 oblique ; maxillary extending to below the nostril ; fold of 

 the lower lip continuous, slightly produced. Cheek with 

 7 or 8 series of scales ; 4 or 5 very short gill-rakers on the 

 lower part of anterior arch. Scales 65-70 ^|, 50-55 in a 

 longitudinal series below the lateral line, 6 between upper 

 and lower lateral lines. Dorsal VIII-IX 30-31 (VII-IX 

 26-31). Anal VIII 27-30 (VII-IX 26-31). Dorsal and 

 anal spines graduated, the fins covered with scales in their 

 basal halves. Pectoral a little longer than the head. Caudal 

 rounded. Caudal peduncle very short. Body with dark 



