CHRYSICHTHTS. 333 



8. CHRYSICHTHYS. 



Bleeker, Act. Soc. Sc. Ind.-Neerl. iv. 1858, p. 60, and Nederl. Tijdschr. Dierk. i. 1863, p. 95 ; 

 Giinther, Cat. Fish. v. p. 70 (1864) ; Boulenger, Poiss. Bass. Congo, p. 277 (1901). 



Body moderately elongate, feebly compressed. Dorsal and anal fins short, the 

 former consisting of a spine and 5 or 6 soft rays and followed by an adipose fin. 

 Pectoral fin with a spine. Ventral fin with 6 rays, inserted behind the vertical of the 

 dorsal fin. Four pairs of barbels : nasal, maxillary, and two mandibulars. Nostrils 

 widely separated from each other. Eyes superolateral, with free border. Jaws with 

 a band of villiform teeth ; a band of teeth on the vomers, often extending also on the 

 pterygoids. Gill-membranes free, deeply notched. Air-bladder large, free. 



10 to 20 prsecaudal and 24 to 27 caudal vertebrae, 16 + 25 in C. auratus, 17 + 24 in 

 C. rueppellii. 9 or 10 branchiostegal rays. A more or less distinct foramen above the 

 axil *, leading to the membrane of the air-bladder. 



All the species are African. Over twenty have been described, but the characters 

 of many of these are still insufficiently defined. One species is known from the 

 Nile, whilst a second, which was first distinguished by Giinther, is perhaps not entitled 

 to stand. 



The fishes of this genus are carnivorous, feeding chiefly on other fishes, crustaceans, 

 and mollusks. C. auratus has been observed in the Gezira Aquarium f to eagerly eat 

 pieces of bread. 



1. CHRYSICHTHYS AURATUS. 

 (Plate LX. fig. 1.) 



Pimelodus auratus, Geoffroy, Descr. Egypte, Poiss. pi. xiv. figs. 3 & 4 (1809). 



Forms auratus, I. Geoffroy, op. oit. p. 302 (1827). 



Abou Crata, Rifaud, Yoy. Egypte, pi. cxcv. (1835). 



Bagrus auratus, Riippell, N. Nachtr. Beschr. Fische Nil, p. 25 (1835) ; Cuvier& Valenciennes, 



Hist. Poiss. xiv. p. 427 (1839). 

 Bagrus capita, Cuvier & Valenciennes, t. c. p. 430. 

 Chrysichthys auratus, Bleeker, Acta Soc. Sc. Ind.-Neerl. iv. 1858, p. 65. 



* First noticed by Eiippell, N. Nachtr. Beschr. Fische Nil, p. 2Q (1835). 

 f S. Flower, Rep. Zool. Gardens Giza, 1903, p. 41. 



