AUCHENOGLANIS. 347 



Like the Synodontis this species makes a creaking noise with its pectoral fins when 

 taken out of the w^ater. It feeds on fishes and crustaceans, probably also on vegetable 

 matter, as the great length of the digestive tract indicates. 



The native name in Lower Egypt, according to Geoffroy, is Karafchi or Schal- 

 Karafche ; in Upper Egypt, Duk Majek or Zamar, according to E-ifaud. 



2. AUCHENOOLANIS OCCIDENTALS. 

 (Plate LXIIL) 



Pimelodus occidentalism Cavier & Valenciennes, Hist. Poiss. xv. p. 203 (1840). 



Auchenaspis biscutatus, part., Giinther, Cat. Fish. v. p. 137 (1864). 



Auchenaspis biscutatus, Steindachner, Sitzb. Ak. Wien, lx. i. 1870, p. 993, pi. vi. figs. 3 & 4. 



Kilnoki, Schweinfurth, Herz. Afr. i. p. 252, fig. (1871). 



Oxyglanis sacchii, Vinciguerra, Ann. Mus. Genova, (2) xix. 1898, p. 250. 



Auchenoglanis biscutatus, part., Boulenger, Poiss. Bass. Congo, p. 296 (1901). 



Auchenoglanis occidentalism Boulenger, Ann. & Mag. N. H. (7) x. 1902, p. 263, 



Auchenoglanis occidentalism var. tanganicanus, Boulenger, Tr. Zool. Soc. xvii. 1906, p. 553, pi. xxxiii. 



Very nearly allied to the preceding, but distinguished by the longer and more 

 pointed snout, which measures usually more than half the length of the head, and 

 three (young) to eight times the diameter of the eye ; maxillary barbel always shorter 

 than the outer mandibular, one-third to a little over one-half the length of the head, 

 not extending beyond the posterior border of the eye. Adipose fin often deeper behind 

 than in A. biscutatus and its outline ascending more gradually. 



Some specimens are uniform olive or brown, whilst others are spotted with dark 

 brown or blackish ; these spots, when present, larger than in A. biscutatus, often very 

 large on the dorsal and caudal tins, where they are separated by a narrow network 

 of the pale ground-colour. 



This species grows to a larger size than its Nilotic congener, reaching a length of 

 one metre. 



It has also a much wider distribution and appears to be the commoner of the two 

 species in the Nile. It was the only one represented in the British Museum until 

 specimens of the true A. biscutatus were sent by Mr. Loat. It is now known from the 

 Lower Nile (Luxor), the Upper Nile, the White and Blue Niles, the Bahr-el-Gebel, 

 Lake Rudolf [Oxyglanis sacchii, Vincig.), Lake Chad, the Senegal, the Niger, and the 

 Congo system, including Lakes Bangwelu and Mweru. The Tanganyika specimens 

 may be regarded as of a distinct variety, which I have described as var. tanganicanus ; 

 the adipose fin is usually lower, the interorbital region narrower, and the outer 

 mandibular barbel is not or but slightly longer than the maxillary, which reaches the 

 posterior border of the eye. 



2*2 



