SOUTH AMERICAN NEMATOGNATHI. 101 



uu. Head depressed, its width at the mouth about equal 

 to its greatest width. Adipose fin shorter than the 

 anal; caudal forked, the rays much branched. Maxil- 

 lary band of teeth much narrowed in the middle; 

 teeth on the vomer separated on the median line, closely 

 joined to the palatine patches, together forming, on 

 either side, a figure somewhat like a comma. Top of 

 head osseus; the occipital process produced, meeting or 

 nearly meeting the dorsal plate; fontanel extending 

 from the middle of the snoiit to behind the eyes and 

 continued to the occipital as a groove. 



PSErDOPLATYSTOMA XXXV. 



mm. Upper jaw greatly produced. 



X. Snout broad, the width at the mouth being equal to the greatest 

 width of the head. Teeth of the upper jaw in a broad crescent- 

 shaped patch. Barbels fleshy. 

 y. Head abnormally depressed, the ej'es strictly lateral. 



SORUBIM XXXVI. 



yy. Eyes su23erior. Sorubimichthys xxxvii. 



XX. Snout long and pointed, the width at the mouth IJ in the 

 greatest width of the head. Teeth of the ujjper jaw in a long 

 arrow-shaped patch; jjalatine patches longitudinally ovate, remote 

 from the vomerine patch. Maxillary barbels very much longer 

 than the body. Platystomatichthys xxxviii. 



XI. PiMELODINA. 



Pimelodina Steinclachner, SB. Ak. Wien, Ixxiv, 1876, 

 Ichthyol. Beitr. v, 101 (jiavipinnis). 



Type: Pir^ielodina flavipinnis Steindachner. 



This genus is characterized by its prolonged, sub- 

 conical snout; by its dentition and by the nature of its 

 fins. 



68. Pimelodina flavipinnis. 



Pimelodina flaviphuiis Steindachner, 1. c. 102, pi. 13, fig. 2 (Amazon 



near Para). 

 Habitat : Para . 



69. Pimelodina nasus. 



Pimelodina tiasus Eigenm. & Eigenm. Proc. Cal. Acad. Sci. 2d Ser. 



vol. i, 1888, 120 (Para). 

 Habitat: Para. 



