•2d. lateralis. With three black spots on each side. 3d. JLeu- 

 cofitera. All the fins pale and whitish. 



72d Species. Silvery Catfish. Fimclodus argtp-us. Piin- 

 elodc argyre. 



Jaws nearly equal, lateral barbs brown and reaching the pec- 

 toral fins. Eyes elliptical. Body silvery, lateral line straight. 

 Fins brownish, anal with 25 rays. Tail equally forked. 



Silurus argenleus. Monograph)', sp. 4. There is another 

 species of that name already. 



A small and rare species, very similar to the foregoing, of 

 whictTit is perhaps a variety. Number of rays similar. 



2d Section. Leptops. Tail bilobed. Eyes round and very 

 small. Nine abdominal rays- Vent posterior. Adipose fins 

 large. 



73d Species. Claatmv Catfish. Pimelodus -vise onus. Pim- 

 clode visqueux. 



Jaws nearly equal, barbs very short, eyes round over the 

 head. Body entirely brown, lateral line raised upwards beiorc. 

 Pectoral fins with 1 and 7 rays, anal fin rounded with 1 5 rays. 

 Tail unequally bilobed and black, upper lobe smaller and white. 



Silurus viscosus. Monogr. sp. 6 



A very singular rind rare species, found at the falla. Length 

 only 4 inches, brown with bluish and greyish shades, covered 

 with a clammy viscosity; throat whitish. Head very flat, with 

 tt longitudinal furrow above, elongated; upper jaw hardly long- 

 er. Eyes over the head very small and bluish. Spines of the 

 anterior fins short, thick, and simple. Dorsal with 1 and 7 rays. 

 Abdominal small with 9. Anal blackish. 



75th Species. Clouded Catjtsu. Pimelodus ncbulosus. 

 Pimelode nebuleux. 



Jaws equal, barbs shorter than the hcr.d. Eyes round, ex- 

 ceedingly small. Body olivaceous, clouded with pale brown, 

 '-white beneath, lateral tine nearly straight. Pectoral fins with 

 } and 9 rays, anal fin rounded with 12 rays. Tail merely 

 notched, hardly but equally bilobed. 



Silu?'U8 ncbulcs'n'-.. Monogis sp. 5. 



This species h totally different from the foregoing, and 

 •might perhaps lorm a peculiar section or even subgenus, (0* 



