294 SILUBIDJE. 



6. CLARIAS CARSONIL 



(Plate LHI. fig. 1.) 



Boulenger, Ann. & Mag. N. H. (7) xii. 1903, p. 362. 



Depth of body six and a half to nine and a half times in the total length, length of 

 head four and one-sixth to five times. Head once and one-fifth to once and one-third 

 as long as broad, smooth ; occipital process angular, not longer than broad ; frontal 

 fontanelle sole-shaped or knife-shaped, twice and a half to three times as long as broad, 

 four or five times in the length of the head ; occipital fontanelle small, in advance of 

 or encroaching a little on the occipital process ; eye three to five times in the length of 

 the snout, six to eight and two-thirds times in the interorbital width; width of mouth 

 a little less than interorbital width ; band of praemaxillary teeth three and a half to five 

 times as long as broad ; vomerine teeth conical, some very obtusely, forming a crescentic 

 band which is about as broad as the praemaxillary band. Nasal barbel two-fifths 

 to three-fifths the length of the head ; maxillary barbel three-fifths to three-fourths 

 the length of the head, not reaching or reaching the gill-opening ; outer mandibular 

 barbel once and one-third to once and a half the length of the inner, which measures 

 one-half to two-thirds the length of the head. Gill-rakers stout and wide apart, 

 10 or 11 on anterior arch. Clavicles hidden under the skin. Dorsal fin with 

 65 to 78 rays, its distance from the occipital process two-fifths to three-fifths the 

 length of the head, its distance from the caudal fin equal to one or two diameters of 

 the eye. Anal fin with 57 to 64 rays, nearly touching the caudal. Pectoral fin about 

 half the length of the head, the spine very indistinctly serrated and measuring about 

 two-thirds the length of the fin. Ventral fin shorter, once and one-third to once and 

 two-thirds as distant from the root of the caudal as from the end of the snout. Caudal 

 fin rounded, half as long as the head. 



Dark brown above, lighter brown beneath. One specimen is yellowish, marbled 

 with brown — probably a pied albino. 



This Clarias does not appear to exceed a length of 285 millimetres, 1500 millim. in 

 the original description being a misprint for 150. 



Clarias carsonii was originally described from a half-grown specimen from Fwambo, 

 a village 21 miles S.S.E. of Lake Tanganyika, presented to the British Museum by 

 Mr. A. Carson in 1894. About twenty specimens, some of w 7 hich agree very closely 

 with the type, were obtained by Mr. Doggett in Lake Victoria and presented to the 

 British Museum by Col. Delme Radcliffe in 1904. Specimens were also obtained in 

 the same lake, at Munyongo and Bunjako, by Mr. Degen in October and November 

 1905. The same fish has also been found in a small river near Fort Portal, 12 miles 

 east of Ruwenzori, altitude 4500 feet, by Mr. R. B. Woosnam in December 1905. 



