ic)i6.] Fauna of the Chilka Lake : Fish. 429 



Distribution: — In the sea, brackish waters and rivers of India, Ceylon, Andaman 

 Islands, the Malay Archipelago and Celebes. 



Subfamily SILURINAE. 



Genus WALLA GO, Bleeker. 



Wallago attu (Bloch and Schneider). 



1801. Silurus attu, Bloch and Schneider, Syst. Ichthyol., p. 378. 



1803. Silurus sp. (wallago), Rüssel, Vizag. Fish., II, p. 50, pi. clxv. 



1822. Silurus boalis, Hamilton Buchanan, Fish. Gang., pp. r54 and 375, pi. xxix, fig. 49. 



1862. Wallago attu, Bleeker, Ail. Ichth., II, p. 79, tab. Ixxxvi, fig. 1. 



1878. Wallago attu, Day, Fish. Ind., p. 479, pi. cxi, fig. 4. 



1889. Wallago attu, Day, Faun. Brit. Ind., Fish., I, p. 126, fig. 54. 



Only one specimen, comparatively young, measuring 253 mm., was collected, at 

 Barkul in September, 1914. The fleshy and triangular anal papilla lies horizontally 

 in a groove behind the anal opening and the ventral fins extend to the first few rays 

 of the anal fin entirely covering the papilla. 



This fish appears to be an occasional visitor to the main area after freshets. 



Distribution : — Fresh waters throughout India, Ceylon, Siam and the Malay 

 Archipelago. The fish is occasionally found within tidal influence. 



Genus CALLICHROUS, Hamilton Buchanan. 

 Callichrous bimaculatus (Bloch). 



1794. Silurus bimaculatus, Bloch, Ausl. Fisch., VIII, p. 24. 



1822. Silurus (Callichrous) canio, Hamilton Buchanan, Fish. Gang., pp. 151,375. 



1842. Silurus indiens, McClelland, Cal. Journ. Nat. Hist., II, p. 583. 



1841. Schübe pabo, Sykes, Trans. Zool. Soc, II, p. 367. 



1878. Callichrous bimaculatus, Day, Fish. Ind., p. 476, pi. ex, figs. 4 and 5. 



1889. Callichrous bimaculatus, Day, Faun. Brit. Ind., Fish., I, p. 131, fig. 57. 



One specimen, measuring 231 mm., was obtained at Barkul in the month of 

 September, 1914. Evidently it entered the lake from some river during the floods. 



Distribution : — Fresh waters of India, Ceylon, Siam and the Malay Archipelago. 

 The fish has been also found within tidal influence in Burma. 



Genus PANGASIUS, Cuvier and Valenciennes. 

 Pangasius pangasius (Cuvièr and Valenciennes). 



1822. Pimelodus pangasius, Hamilton Buchanan, Fish. Gang., pp. 163 and 376, pi. xxxiii, fig. 52. 



1840. Pangasius buchanani, Cuvier and Valenciennes, Hist. Nat. Poiss., XV, p. 45. 



1878. Pangasius buchanani, Day, Fish. Ind., p. 470, pi. cviii, fig- 5- 



1889. Pangasius buchanani, Day, Faun. Brit. Ind., Fish., I, p. 142, fig. 61. 



Two young specimens, measuring 104 mm. and 85 mm. respectively, were collec- 

 ted about eight miles south-east of Kalupara Ghat on the 16th September, 1914. 

 They evidently came to the lake along with the freshets. There is a thick anal papilla 



