336 On anew Species of Pimelodus. 



in the waters of the kingdom of Quito. I have designed it^ 

 with care, on the spot, and my design has been coloured by 

 M. Turpin. I have observed that the premiadilla is a new 

 species of the genus silurus. M. Lacepede, who has also 

 examined it, advised me to place it in that division of silurus 

 which, in the fifth volume of his Natural History of Fishes, 

 he has described under the name oi pimelodes. 



This new species of pimelodus has a depressed body of an 

 olive colour mixed with little black spots. The mouth, which 

 is at the extremity of the nose, is very large, and furnished 

 with two barbillons or whiskers attached to the jaws. The 

 nostrils are tubulous ; the eyes are very small, and placed 

 towards the middle of the head. The skin of the body and 

 the tail is covered with an abundant mucus, and the mouth 

 is furnished with very small teeth. The branchial membrane 

 has four radii, like the pimelodus chilensis ; the pectoral fin 

 has nine; the ventral five; the first dorsal six; the fin of the 

 anus seven ; and that of the tail, which is bifid, has twelve 

 radii. The first radius of all the fin? is indented on the out- 

 side : the second dorsal fin is adipose, and placed near the 

 tail. This little pimelodus, v/hich is found in lakes even to 

 the height of 170O toises, is, uilhout doubt, the fish that 

 lives in the most elevated regions of our globe. Its common 

 length scarcely amounts to ten centimetres (four inches) j 

 but there are varieties which do not appear to reach five cen- 

 timetres (two inches) in length. 



In the system of ichthyology this new species oi pimelodus 

 should be ranged in the first sub-genus established by Lace- 

 pede, among the forked-tailed pimelodes. It must be in the 

 first species, before the pimelodus bagre. As it is the only 

 one of that division that has but two whiskers, I give it the 

 name of 



PIMELODUS CvcLOPUM. (Plate VIII.) 

 Cirris duobus, corporc olivaceo nigro-pimctato. 



This little fish lives in rivulets at the temperature of 10° 



of the centigrade thermometer, while other species of the 



same genus e\ist in rivers in the plains the water of which is 



at 27°. The pimelodus is but very rarely eaten, and then 



4 only* 



