114 silurid^:. 



the head. Adipose fin rather longer than the dorsal. Brownish, 

 with two curved whitish longitudinal bands ; large dark-brown spots 

 on the dorsal fins ; barbels annulated with white and brown. 

 Barra do Bio ITegro. 



2. Sciades longibarbis. 



Arius (?) longibarbis, Casteln, Anim. nouv. ou rares Atner. Sud, p. 36. 

 pi. 15. fig. 2. 



D. 1/11. A. 9. P. 1/11. Y. 1/5. 



Teeth on the palate in two separate, transversely ovate groups. 

 Barbels very long. Dorsal spine slender, much shorter than the 

 head. Adipose fin as long as the dorsal. Body variegated with 

 grey, black, and white. (Casteln.) 



Amazons. 



53. PIMELODUS*. 



Pimelodus, sp., Lacep., Cuv. ty Val. 



Rhamdia/' Pseudorhamdia, et Pseudopimelodus, Bleeker, Nederl. 



Tydschr. Dierk. 1863, p. 101. 

 Pimelonotus, Pimelodus, et Batrachoglanis, Gill, Ann. Lye. Nat. Hist. 



New York, 1858, p. 387. 



Adipose fin well developed ; dorsal fin short, with a more or less 

 pungent spine and with six, exceptionally with seven or eight, rays ; 

 anal fin short. Barbels six, subcylindrical or slightly compressed. 

 Teeth villiform, in both jaws, in bands which are broader than long ; 

 palate edentulous. Nostrils distant. Gill-membranes separated by 

 a deep notch at the throat. Ventrals six- rayed, inserted behind the 

 dorsal. 



Tropical America (Asia?, Sandwich Islands?). 



We refer the numerous species of this genus to the following 

 divisions, which, however, pass into one another by intermediate 

 forms : — 



A. Head granulated above; dorsal spine strong: Pseudorhamdia, sp., 



Bleek., p. 115. 



B. Head not granulated; the occipital process extends on to the basal 



bone of the dorsal spine; dorsal spine feeble: Pseudorhamdia, sp., 

 Bleek., p. 117. 



* 1. Pimelodus charus, Cuv. $ Val. xv. p. 159. — Brazil. 



2. zungaro, Humboldt, Observ. Zool. ii. p. 170. pi. 46. fig. 1 ; C. $ V. 



xv. p. 160. — Zungaro humboldtii, Bleek. Nederl. Tydschr. Dierk. 1863, 

 p. 101. — River Maragnon. — This fish is stated to have ten ventral rays. 



3. argentinus, Humboldt, Observ. Zool. ii. p. 171. — Magdalena River. 



4. velifer, Humboldt, I. c. — Magdalena River. 



5. maculatus, Schomb. Fish. Guian. i. p. 175. — Rhamdia schomburgkii, 



Bleek. Prodr. Silur. p. 208. — Brazils, Guiana. 



6. Laukidi, Schomb. I. c. p. 176. — Rhamdia laukidi, Bleek. 1. e. — Brazil, 



Guiana. 



7. Pimelodus insignia, Schomb. I. c. p. 180. pi. 6. — Rio Branco. — This fish 



is said to have ten ventral rays like P. zungaro. 



8. bahianus, Casteln. Anim. Amir. Sud, Poiss. p. 35. pi. 16. fig. Ii.— 



TCfthia. 



