58. ArciiENASPis. 137 



tending on to the basal bone of the dorsal si)ine. No other teeth 

 behind the front series in cither of the jaws. The maxillary barbels 

 extend to, or beyond, the base of the caudal. Some roundish dusky 

 spots along the side. {Gill.) 

 Amazons River. 



2. Callophysus macropterus. 



Pimelodus macropterus, Lichtemt, in Wiedem. Zool. Mag. i. part 3. 



1810, p. 59. 

 Callophysus macropterus, Mull. ^ Trosch. Hor. Iclith. iii. p. 1. 



B. 7. D. 1/6. A. 12. P. 1/12. V. 6. 



The occipital process does not extend on to the small basal bone 

 of the dorsal spine. A second series of small teeth behind the front 

 series in the upper jaw ; no second scries in the lower. The maxil- 

 lary barbels extend to the base of the caudal, the outer ones of the 

 mandible not quite to the end of the ventrals. (ilf. 4" T.) 



Brazil ; Guiana. 



3. Callophysus ctenodus. 



Pimelodus ctenodus, Aijass. in Spix, I'isc. Bras. p. 21. pi. 8 a. 

 D. 1/6. A. 10. P. 1/14. V. 7. 

 The occipital process does not extend on to the small basal bone 

 of the dorsal spine. A second series of small teeth behind the front 

 series in the lower jaw. The niaxiUaiy barbels extend beyond the 

 anal, the outer ones of the mandible beyond the pectoral. (^Afjass.) 

 Brazil. 



58. AUCHENASPIS. 



Auchenaspis, Bleek. Neclerl. Tydschr. Dierk. 1803, p. 101. 



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

 with seven rays ; anal short. Snout produced, pointed, with narrow 

 mouth ; barbels six. The teeth of each jaw form a pair of small 

 elliptic patches which arc longer than broad ; palate edentulous. 

 Nostrils distant from each otlicr ; eyes of moderate size. Gill- 

 membrane scarcely notched at the throat. Ventral with six rays. 



Tropical Africa. 



1. Auchenaspis biscutatus. 



Pimelodus biscutatus, Qeoffr. Dencr. Ef/i/pt. Zool. Poi-sx. pi. 14. figs. 1 &2; 



Cm: ^- Val. xv. p. 197. 

 occidentalis, Cuv. l^- Val. xv. p. 203. 



B. 9. D. 1/7. A. 11-12. P. 1/9. 

 Head coarsely granulated above ; occipital process very broad, with 

 the lateral margins convex, joining the very large sadcUo-shaped 

 dorsal plate. Snout produced, pointed, with broad lips and ^Wth a 

 narrow mouth. Barbels cylindrical, shorter than the head, the 

 outer ones of the mandible being shorter than those of the maxil- 

 luries. Dorsal and pectoral .spines strong, nearly equal in length, 

 rather more than half as loim as the head. The length of the adi- 



