PISCES. 85 



Sp. Synodontis macrodon ISID. GEOFFB. SAINT-HILAIBE, Silurus Clarias 

 HASSELQUIST ; Synod, ardbi VALENC., Silurus schal BLOCH, Syst. Ichth., 

 SONNINI Voyage en Egypte, PL 21, fig. 2 ; Synod, serratus RUEPPELL, 

 Beschr. und Abbild. neuer FischeimNil entdeclct, 4to. 1829, Tab. II. Synod, 

 maculosus RUEPPELL, ibid. Tab. in. fig. i. 

 All the known species are found in the Nile. 



Pimelodus VALENC. (species of Pimelodus LACEP.). Body 

 naked. Teeth in maxillae very thin, crowded, sometimes none; 

 palate edentulous. Branchiostegous membrane mostly with eight 

 ravs (5 12). Dorsal fins two, the second adipose, frequently small, 

 placed above the anal. Cirri six or eight. 



Sp. Pimelodus Sebce Cov., Silurus clarias L., excl. synon., SEBA Tkesaur. m. 

 Tab. 29, fig. i ; Pimelodus catus Cuv., Silurus catus L., Cuv. et VALENC. 

 Poiss. xv. PI. 432, &c. 



The species of this genus are very numerous in warm regions, especially 

 in the western hemisphere. 



Calophysus MUELL. and TROSCH. ! 



Hypophthalmus SPIX (in part), YALENC. Teeth none. Eyes 

 placed at the inferior margin of jaw. Branchiostegous membrane 

 with fourteen or fifteen rays. 



Sp. Hypoplithalmus marginatus VALENC., Cuv. et VALENC. Hist. not. des 

 Poiss. xv. PI. 439 -,HypophtJi. Spixii VAL., Hypophthalmus edentatus 

 SPIX, &c. 



Ageneiosus LACEP., YALENC. 



Ketengus BLEEKER. Genus unknown to me, with four cirri 2 . 



Arges YALENC. Teeth bifid at the apex. Branchiostegous mem- 

 brane with four rays. Eyes small. Cirri two. 



Sp. Arges Sabalo VAL., Hist. not. des Poiss. PL 444, Peru. 



To this genus VALENCIENNES refers the small species of fish which HUM- 

 BOLDT has described under the name of Pimelodus cyclopum, and which 

 lives in brooks in the high ranges of Quito. It resides also in subterranean 

 lakes, which appear to communicate with the volcanos of these regions, at 

 least if, as the natives assert, it is the same species which is ejected with 

 mud from the Cotopaxi sometimes by thousands. HUMB. Recueil d'Obser- 

 rations de Zoologie et d'Anat. compar. I. pp. 21 25, PL 7. 



1 Compare MUELLEB and TBOSCHEL Horce Ichthyologic^e, 3, 1849, pp. i, 2. 

 3 P. BLEEKEB, Nieuwe Bijdrage tot de Kennis der Siluroieden von Java. Batavia, 

 $46, p. 9. 



