SILTJEANODON. 319 



the head; mandibular barbels close together on the chin, equal in length, or inner a 

 little longer than outer, about one-third of the total length. Gill-rakers long and 

 setiform, 50 to 60 on lower part of anterior arch. Dorsal fin small, with 5 rays, all 

 except the first very feeble and close together, the base of the fin being extremely 

 short ; its distance from the caudal fin twice and a half to three times that separating 

 it from the end of the snout, xinal fin with 74 to 85 rays, of equal length throughout, 

 and about half the length of the head, nearly reaching the caudal fin. Pectoral fin 

 rounded, a little longer than the head, extending beyond the base of the ventral, its 

 spine feeble, smooth, without any serration, and about three-fourths to four -fifths the 

 length of the fin. Ventral fin one-third to two-fifths the length of the head, inserted 

 below the dorsal, or just behind the vertical of its base. Caudal fin notched, with 

 rounded or obtusely pointed lobes, the upper a little longer than the lower. 



Coloration silvery, the head and a dorsal band dull greyish brown, finely speckled 

 with blackish, this band extending on the upper lobe of the caudal fin ; a red spot, 

 shot with gold, on the gill-cover ; a more or less distinct dark blotch behind the 

 shoulder; sometimes a dark streak above the lateral line; dorsal fin often blackish; 

 caudal fin often edged with blackish ; anal fin often speckled with blackish, especially 

 on the lower half. 



This fish does not appear to exceed a length of 175 millimetres. 



Discovered by Geoffroy Saint Hilaire in the Lower Nile at the close of the eighteenth 

 century, this little Silurid remained one of the rarest in collections. The first 

 specimens received by the British Museum were presented by Dr. J. C. Mitchell in 

 1896. Numerous examples were obtained by Mr. Loat in the Lower Nile, at Assuan, 

 and in the White Nile. I have been able to examine 101 specimens : — 



1 Damietta branch of Nile, downstream side o£ barrage. — Loat, 3.8.99. 

 42 Rosetta branch of Nile, downstream side o£ barrage. — Loat, 28-31.7.99. 



2 Near Cairo.— Dr. J. C. Mitchell, 1895. 

 1 Nile at Luxor.— Loat, 21.10.00. 



1 At a regulator near Luxor. — Loat, 3-10.11.99. 



1 Between Assiut and Abu Tig. — Loat, 1.12.99. 



28 Assuan.— Loat, 10-30.9.00. 



6 G-harb-el-Aish, White Nile, in a kore. — Loat, 6-14.4.01. 



14 Fashoda, in a kore. — Loat, 14-31.3.01. 



5 Mouth of Lake No.— Loat, 4.2.01. 



Females full of ripe roe occurred in the Rosetta Nile at the end of July ; males 

 are a little smaller. As observed by Geoffroy, in accordance with the inferior 

 position of the eyes, this fish often swims inverted, with the belly upwards ; its 

 large rounded pectoral fins have suggested to the natives a pair of ears, whence the 

 name " Oned denne " (U j u^oj), " with ears," which is expressed by the scientific name 



