SOUTH AMERICAN NEMATOGNATHI. 



107 



Luciopimelodus pati Eigeum. & Eigenm. Proc. Cal. Acad. 2d Ser. 



vol. i, 122 (Buenos Ayres). 

 Habitat: Pio Plata; Eio Braiico near British Guiana. 



Width below the first dorsal spine less than the depth, 

 tapering to a slender caudal peduncle. Head wide, its 

 width If in its length; snout elongate, depressed, spatu- 

 late, its width at the rictus 2 in length of head; upper 

 half of cheek, nasal and occipital regions covered with 

 reticulated skin. Occipital process a mere ridge. 



Eye behind the middle of the head, 5J in snout, 11 in 

 head, 2f in interorbital, 3f diameters behind the rictus; 

 mouth large, the upper jaw 

 slightly projecting; width of the 

 mandibulary band of teeth equal 

 to the diameter of the eye; in- 

 termaxillary band of teeth deep- 

 est at the outer edges which are 

 emarginate. 



Maxillary barbels somewhat compressed, reaching to 

 tips of ventrals or beyond region of anal; mentals in- 

 serted almost directly in front of the postmentals, reach- 

 ing beyond base of pectoral; postmentals beyond base 

 of ventrals. 



Gill-rakers short, scarcely overlapping, 4-J-13. 



First dorsal ray slender, articulated on its upper half, 

 but not branched, longer than the following rays, 1| in 

 head; dorsal rays rapidly decreasing in height to the 

 last, which is less than one-half as high as the first. Adi- 

 pose fin 3J 4J in the length. 



Caudal deeply forked, both lobes long and pointed, 

 about equal to the head in length. 



Free margin of anal emarginate, the fourth ray high- 

 est, 2-J- in head. 



Ventrals inserted behind the vertical from last dorsal 

 ray, 1-f-lJ in the head. 



