( 17 ) 



sometimes going long distances up their course : thus, I have 

 taken Lates calcarifer at Mandalay in Upper Burma, about 

 650 miles from the sea, evidently following the shoals of 

 shad, Clupea palasah, for predaceous purposes. 



XXIX. Eishes of the order PHYSOSTOMI, or those in 



which the air-vessel communicates 



Physotomatous order of fishes. .,, ., i / 



or those possessing a connecting with the pharynx by means of a 

 duct between air-vessel and pneumatic duct, contain the largest 



proportion of the Indian fresh-water 



fishes. One of these families (Silurida) are destitute of 

 scales, whilst they are present in the Cyprinida, which have 

 no teeth in the jaws or palate, and also in the herrings 

 (Clupeidce), the majority of which last have a trenchant or 

 cutting abdomen (as the hilsa, Clupea palasah), or generally 

 a few minute teeth in the jaws or palate. The Notopteridce, 

 which also belong to this order, furnish some species which 

 are esteemed by the natives. 



XXX. The siluroid family, siluridce, are commonly 



Silurid* or scaleless fishes, knOWn aS Cat-fisheS, because they 



often termed cat-fishes, as they generally possess a number of long 

 generally have long feelers. barbels, arranged around the mouth. 

 These fishes mostly prefer muddy to clear water, as such 

 conceals their presence. The more developed and numerous 

 these barbels, the better adapted these fish seem to be for an 

 inland and muddy fresh- water residence; whilst on the con- 

 trary, those which are strictly marine do not appear to be so 

 well furnished with these appendages. Siluroid fishes are also 

 generally armed with strong spines in the fin of the back 

 and pectoral fins, and which, as a rule, are serrated ; with these 

 severe wounds are often inflicted, which renders the handling 

 of them dangerous. Tropical countries, which possess large 

 and muddy rivers and tanks in their plains, such as Bengal 

 and Burma, are more adapted for siluroids than such localities 

 as Madras, where the rivers are smaller, and the waters 

 clearer. Irrespective of being scaleless or unclothed (if we 

 admit scales to be the clothing of fish), they would hardly 

 appear to be suited for cold climates, and we find that they 

 are much more numerous in tropical than in sub-tropical 

 or temperate parts of the globe. The siluroid fishes which 

 are captured in the fresh-waters mostly belong to the follow- 

 ing 25 genera, excluding Chaca, some of which are marine, 

 others not so : 1, Akysis ; 2, Erethistes ; 3, Macrones ; 

 4, Rita; 5, Arius ; 6, Pangasius ; 7, Pseudeutropius ; 

 8, Callichrous ; 9, Wallago ; 10, Olyra ; 11, Silurus ; 12, 

 Clarias ; 13, Saccobranchus ; 14, Silundia ; 15, Ailia ; 16, 



