OCR Text |
Show 1871.] FRESHWATER SILUROIDS OF INDIA. 707 Eyes of moderate size, situated nearer the snout than the posterior half of the head. Width of head equals its height, and is as long as the head without the snout. Groove on the summit of the head lanceolate in its posterior half and extending to the base of the occipital process, which is twice as long as wide at its base, and reaches the basal bone, which is V-shaped. Nasal barbels extend to the posterior margin of the orbit, the maxillary to the middle or end of the pectoral fin, the external mandibular are as long as the head, the internal shorter. Teeth in an uninterrupted crescentic band on the palate. Fins. Dorsal spine smooth, as long as the head without the snout, whilst the fin is as high as the body below it; adipose fin small, its base shorter than that of the first dorsal. Pectoral spine as long as the head without the snout; it is strongly serrated internally. Caudal deeply lobed, the upper slightly the longest. Colours. Golden, with three or four longitudinal bands formed of black spots in the upper one along the back, and black stars in the lower ones. A darkish blotch formed of spots over the base of the pectoral fin; some spots on the dorsal and the margins of the other fins stained. Hab. Assam and the Punjaub ; attaining about 3 inches in length. Hamilton Buchanan observes, all the barbels are shorter than the head; but m y specimens so exactly resemble his figure and description, except in the maxillary barbels being longer (and they varied in individuals), that I consider they must be the same. I took upwards of twenty in a tank near Goordaspoor in the Punjaub. This genus, containing mostly only inhabitants of fresh waters, still has estuary or marine representatives (M. gulio, H. B.). It is found generally throughout India and Burmah, down to the Malay archipelago. RITA CRUCIGERA, Owen. Pimelodus ritu, Hain. Buch. pl. 24. f. 53. I have found this species throughout the extent of the Ganges and Jumna, and also in the Punjaub rivers; but it is subject to considerable variation, due to age and locality. The dorsal spine may be as long as, or longer than, the head, the pectoral being somewhat shorter, whilst the humeral process, although not pointed, is but very slightly rounded. Air-vessel with a thick outer coat and thin lining membrane. Its external form is somewhat quadrangular; and posteriorly it is continued into two horn-like processes, nearly or as long as the abdominal cavity ; the right one usually passing over to the left side and curving across the commencement of the left one, whilst the left one first passes downwards and then is sometimes recurved on itself. On the front wall being removed a longitudinal median partition is seen in its posterior half, dividing it into two large smooth cavities, which anteriorly communicate, and are continued posteriorly down the hornlike or tubular processes. This genus extends throughout the larger rivers of India and |