eigenmann: tetragonopterid characins. 97 



Compressed, dorsal and ventral profiles equally arched. 



A silvery lateral band, an obscure humeral spot ; middle caudal rays hyaline 

 with traces of color, the tips dark, the caudal lobes opaque. 

 One specimen, about 68 mm. long. Bio Jequitiukonha. 



Astyanax giton, sp. nor. 



These two specimens are Astyanax laeniatus, with a blunt snout. The larger 

 may be considered the type. They differ from A. brevirhinus in the color of the 

 caudal and the shape of the occipital process. 



Head 4; depth 2.5-2.6; D. 11; A. 23-24; scales 5-35-4; eye 2.5; inter- 

 orbital 2.75-3. 



Occipital process not nearly so narrow as in A. brevirhinus ; snout a little more 

 than half as long as the eye. 



A prominent humeral spot crossing the third scale of the lateral line ; a large 

 spot at base of caudal continued to tips of the middle rays. Otherwise as in 

 A. brevirhinus. 



Two specimens, about 68 to about 78 mm. Rio Parahyba. 



Astyanax albeolus, nom. nov. 



Astyanax oerstedii Meek, not Kroyer, Field Columbian Museum, Publication 

 1907, vol. 7, p. 145. 



Head 4.5; depth 2.66; D. 11; A. 26; scales 7-38-7; eye equal to snout, 

 3.5 in head ; interorbital \ the head's length behind the second nareal opening. 



A vertically oval humeral spot, the ventral prolongation scarcely evident, 

 crossing the third and fourth scales of the lateral line. Dorsal whitish, having 

 very few chromatophores ; anal lobe without chromatophores, the rest of the fin 

 with a few. 



Very closely related to A. globiceps. 



One specimen, 116 mm. Rio Machuca, Rio Siguires, Costa Rica. 



Astyanax faseiatus parahybae, subs p. nov. 



The specimens from the Parahyba basin differ from typical A . faseiatus in so 

 many and so striking respects that they may also be distinguished by a varietal 

 name. 



Head 4.25-4.4 ; depth 2.5-2.66 ; H. 11 ; A. usually 31 or 32 (27-34 in A. fas- 

 eiatus) ; lateral line usually 39 or 40 (37-41). 



Rows of scales below the lateral line defected toward the anal by interpolated 

 rows of scales, the first of the interpolated rows beginning at a point above middle 

 of ventrals and one or two rows of scales below the lateral line. 



Tips of dorsal, caudal rays, aud anal usually dark ; tips of ventrals, sometimes 



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