192 THE FISHES OF MALABAR. 



slightly the longest, but in adults the lower is the longest, and curved upwards at its extremity. 

 Preopercle narrow, a third as broad as high. Posterior nostril the largest, nearly circular, and 

 situated near the mesial line : the anterior rather below and in front on the anterior surface of 

 the snout. Occipital process covered by very thin skin, slender, and joining the basal bone of the 

 dorsal fin, which is triangular, and half as long as the occipital process. A central longitudinal 

 groove, which becomes almost imperceptible in the adult, exists along the central line of the skull 

 to the base of the occipital process. The pair of maxillary cirri extend as far as the anterior margin 

 of the anal fin : the nasal pair are fine, and not so long as the head : the two pairs of labial cirri 

 arise close together, nearly under the symphysis, and are as long as the head. 



Teeth — In both jaws sharp and villiform, in two rows along the sides, but more numerous in 

 the centre. Teeth on palate in two small oval patches. 



Fins — Dorsal arises opposite the posterior third of the pectoral : ventral under the termination 

 of the dorsal : anal about midway between the snout and the base of the caudal : adipose dorsal 

 arises over the thirtieth ray of anal. First dorsal rounded, spine slender, two-thirds the length 

 of the head, and finely serrated posteriorly : interspinous membrane deeply notched. Pectoral 

 spine strong, much more so than that of the dorsal, and as long as the head without the snout ; its 

 internal margin has from twenty to twenty-five serratures. Ventral very small, not extending as 

 far as the anal. The first ray of the anal the longest : the distance between the end of the anal 

 and the commencement of the caudal fin, equals two-thirds of the depth of the base of the 

 caudal. Caudal rather deeply lobed. 



Lateral line — First curves downwards, and then passes direct to the centre of the caudal. 



Colours— Upper surface of head of a deep grey. Body green, abruptly changing a short 

 distance above the lateral line, where it becomes a beautiful silvery white, which is continued on 

 to the abdomen. Dorsal, pectoral, anal, and caudal white, the last two fins being stained with 

 grey at their bases. 



By no means rare in the rivers of Malabar. In two instances the second or adipose dorsal 

 fin was deficient, perhaps lost by some accident. No doubt it was from some such deformed speci- 

 men that Dr. Jerdon has described this fish. 



Does not grow to above eight inches in length. 



Habitat — Rivers of Malabar. 



Sub-Fam. SILURIFORMES, Bleeker. 

 Group silurini, Bleeker. 



Genus WALLAGO, Bleeker. 



Branchiostegals, fifteen to twenty-one. Neck not elevated, the upper profile of the head being straight. 

 Eyes above or on a level with the angle of the mouth. Snout rather produced ; head covered with soft 

 skin : nostrils remote. Cirri four, one on each supramaxillary, and one on either mandibula. One very short 

 dorsal above or before ventrals, and without any sharp spine. No adipose dorsal. Anal elongated, and 

 terminating near the caudal, which is long and has two rounded lobes. The pectoral spine moderately 

 strong ; serratures weak or absent. Teeth villiform, in many rows in the jaws, and in an oblong patch on 

 either side of vomer, but separated by an interspace : none on the palate. 



