SOUTH AMERICAN NEMATOGNATHI. 107 



Luciopimelodtis pati Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. 



vol. i, 122 (Bueuos Ayres). 

 Habitat: Pio Plata; Eio Brauco near British Gniana. 



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, 5| in snout, 11 in 

 head, 2| in interorbital, of 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 3^-4^ 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| in head. 



Ventrals inserted behind the vertical from last dorsal 

 ray, l|-li in the head. 



