402 On neio Characinid Fishes from South America. 



LII. — Description of Two new Char acinid Fishes from j 

 South America. Bj C. Tate Regan, M.A. ^ 



MiMAGONIATES, gen. nov. 



Body moderately elongate, compressed ; abdomen keeled, 

 but not strongly compressed to an edge. Mouth small ; teeth 

 tricus|)id, in a single series; no maxillary teeth; palate 

 toothless. Nostrils close together. Gill-membranes not 

 united, free from the isthmus. Scales cycloid, of moderate 

 size ; lateral line incomplete. Dorsal fin short, posterior in 

 position; adipose fin present ; anal tin elongate. 



Intermediate between Chirodon^ Girard, and Leptagonlates, 

 Blgr. 



Mimagoniates Barheri, sp. n. 



Depth of body 3 to 3| in the length, length of head 4 to 

 4§. Snout much shorter than eye, the diameter of which is 

 2^ to 2| in the length of head and a little less than the inter- 

 orbital width. Cleft of mouth nearly vertical ; maxillary 

 not extending to below the eye. 42 to 45 scales in a longi- 

 tudinal series ; lateral line on 4 to 8 scales only. Dorsal 10 ; 

 origin equidistant from gill-opening and base of caudal, above 

 the anterior part of the anal. Anal 34-38 ; origin equidis- 

 tant from anterior part of eye and base of caudal ; anterior 

 rays the longest, about g the length of head; free edge 

 straight or slightly concave. Pectoral extending to or a 

 little beyond tlie base of ventral. (Jaudal forked. A lateral 

 band (blackish in preserved specimens) from the lower part 

 of eye to the lower lobe of caudal. An oblique dark stripe 

 on the dorsal ; anal with a dark margin. 



Ilah. Arroyo Yaca, Estacion Caballero, Paraguay. 



Several specimens, the largest 40 mm. in total length, 

 collected by Dr. A. Barbero. 



Ctenochaeax *, gen. nov. 



Body oblong, compressed ; abdomen rounded. ]\Iouth 

 small ; teeth slender, subconical, in a single series ; maxillary 

 toothed ; palate toothless. Nostrils close together ; gill- 

 membranes not united, free from the isthmus. Scales cycloid, 

 rather large ; lateral line incomplete. Dorsal fin short, nearly 

 entirely in advance of the rather short anal ; no adipose fin. 



llelated to Aphyocliarax, Gthr. 



* The name Ctenoduirax is giveu on account of the comb-like appear- 

 ance of the single series of teeth in the jaws. 



