1 10 SILFRID-E. 



head is not covered by the skin. Barbels six. Caudal forked ; ven- 

 trals with six rays, inserted below the last dorsal rays. GiU-mem- 

 branes not united. 

 Brazil. 



1. Platystomatichthys sturio. 

 Platystoma sturio, Kner, Sitzungsher. Wien. Acad. xxvi. p. 395. fig. 9. 

 B. 9. D. 1/6. A. 15. P. 1/9. 



The projecting part of the upper jaw is two-fifths of the length of 

 the head, and densely covered with villiform teeth below. The max- 

 illary barbels are one-third longer than the whole fish. Adipose fin 

 rather longer than anal. 



Eio Branco. 



48. PHRACTOCEPHALUS. 

 Pliractoceplialus, Affass., in Spix, Pise. Bras. p. 22. 

 Adipose fin subdivided into rays, without spine ; a short dorsal 

 fin with a pungent spine and with seven soft rays ; anal fin short. 

 Barbels six. Patches of villiform teeth on the palate ; the upper 

 jaw is the longer. Caudal forked ; ventral with six rays. 

 Tropical America. 



1. Phractocephalus hemiliopterus. 



Sihirus hemiliopterus, Bl. Schii. p. 385. 

 Pirarara bicolor, Spix, Pise. Bras. tab. 6. 

 Phractoceplialus bicolor, Agass. in Spix, Pise. Bras. p. 23. 

 hemiliopterus, Cup. 8f Val. xv. p. 3. pi. 421. 



B. 9. D. ]/7. A. 9. P. 1/9. 



Occipital process very large, semicircular ; basal bone of the first 

 dorsal spine large, kidney-shaped. Dorsal spine not serrated. 

 Bro'wnish black above, greyish below, both coloui\s separated by a 

 white lateral band ; the upper parts of the head with black spots ; 

 fins black. Vomerine teeth in a large pentagonal patch, those of the 

 palatine bones in a tapering band. 



Brazils. 



a. Thirty-eight inches long : stuffed. 



h. Fine specimen. Eiver Cupai (Amazon), 800 miles from the sea. 

 Purchased of Mr. Stevens. 



49. PIRAMUTANA. 



Piramutana et Pseudariodes, Bleelx. Nederl. Tyclseh: Dierk. 1863, p. 99. 



A long adipose fin ; a short dorsal fin with a pungent spine and 

 with six soft rays ; anal fin short. Barbels six. Teeth on the pa- 

 late ; jaws equal in length. The upper surface of the head granular. 

 Caudal forked ; ventrals with six rays, inserted below the end of the 

 dorsal. 



Brazil. 



