47. PLATTSTOMATICHTHYS. 109 



lary barbel extends on to the caudal fin, which sometimes is much 

 prolonged, the outer mandibular}'- barbel to the ventral or anal. Eye 

 in the middle of the length of the head. Dorsal spine slender, scarcely 

 serrated behind ; pectoral spine very slender, four-fifths of the length 

 of the head ; adipose fin longer than the anal. Uniform brownish. 

 Cayenne and Surinam. 



a. Adult : stuffed. Demerara. Purchased of Mr. Scrivener. 

 b-c. Adult. Demerara. Purchased of Mr. Scrivener. 



11. Platystoma affine. 



Cuv. 8f Val. xv. p. 24. 



B. 11. D. 1/6. A. 13. 



The upper jaw projects but little beyond the lower. The maxil- 

 lary barbels extend on to the anal fin. The occipital process does 

 not meet the basal bone of the dorsal spine. Adipose fin rather 

 shorter than anal. Coloration uniform. (Fa/.) 



Hab. ? 



46. HEMISORUBIM. 



Platystoma, sp., Cuv. <§• Val. 



Hemisorubim, Bleek. Nederl. Ti/dschr. Dierk. 1863, p. 97. 



Adipose fin rather long ; a short dorsal fin with a pungent spine 

 and with six soft rays ; anal fin rather short. Snout very long, spa- 

 tulate, with the lower jaw longest. Eyes directed upwards. Teeth 

 on the palate. The upper surface of the head is not covered by the 

 skin. Barbels six. Caudal forked ; ventrals with six rays. Gill- 

 membranes not united. 



Brazil. 



1. Hemisorubim platyrhynchus. 



Platystoma platyrhynchos, Cue. <$• Val. xv. p. 27 ; Kner, Sitzungsber. 

 Wien. Acad. xxvi. p. 398. 



B. 10-11. D. 1/6. A. 11-12. P. 1/9. 



Vomerine teeth in a semicircular band, palatine teeth in longitu- 

 dinal bands. The occipital process is narrow, and meets the basal 

 bone of the dorsal spine. Dorsal spine slender, finely serrated. The 

 maxillary barbel extends to, or beyond, the ventral. A series of five 

 or six rounded blackish spots on each side. 



Rio Negro. 



47. PLATYSTOMATICHTHYS. 



Platystoma, sp., Kner. 



Platystomatichthys, Bleek. Nederl. Tydschr. Dierk. 1863, p. 98. 



Adipose fin of moderate length ; a short dorsal fin with a pungent 

 spine and with six soft rays ; anal fin rather short. Snout very 

 long, spatulate, with the upper jaw much produced. Eyes with a 

 free orbital edge. Teeth on the palate. The upper surface of the 



