PLATANISTA. 419 



out all the main river, as far eastwards as longitude 95° by latitude 27" 30' north, 

 frequenting also aU its larger streams. In the Indus it is found all the year round, 

 from latitude 24° to latitude 34° north, being also distributed through the Jhelum, 

 Chenab, Ravi, and Sutlej rivers up to their exits from the hills ; the area over which 

 it ranges in that part of India being included between the 68th and 77th degrees of 

 longitude. It has thus a permanent distribution in these river systems over 12° of 

 latitude and 27° of longitude ; or, in other words, it has 800 miles of a northerly dis- 

 tribution from its lowest point of range, 22° latitude, as it occurs in the Ganges, 

 with 1,880 miles of lateral extension. 



The upward range of this dolphin is apparently only Umited by insufficiency of 

 water, and by rocky bai'riers. As pointed out by Wallich, Hardwick's specimen was 

 obtained 1,000 miles above Calcutta, and Cuvier remarks that it ascends the Ganges 

 in great numbers as Mgh as the river is navigable. Even in the month of May, 

 when the Ganges is very low, it extends up the Jumna as far as Delhi, and also enters 

 for a short way aU the larger affluents of the main stream. In the Brahmaputra, at 

 the same season of the year, it is found throughout the river as far north-east as 

 Dibrugarh, and it probably extends beyond that point, for it is permanently present 

 in such rivers as the Dihing, Dhansiri, Dikhu, and Disang. From the patrol of 

 Kalabagh on the Indus, it is reported to be constantly present, which is also its 

 habit in the Ravi and in the Sutlej, but it is said to have been found in the Indus, 

 in April, as high up as Attock. The reports, however, all unite in confirming the 

 natural anticipation that it has its widest range in the height of the rains, when the 

 rivers are in flood, and that its distribution is most limited in the hot months when 

 the rivers are low. 



According to my own observations it is more frequently seen in the Hughh at 

 Calcutta, and such distances from the sea in the cold weather, than during the height 

 of summer and the rains, and this coincides with what was observed by Blyth and 

 Cantor ; but the latter conjectured that it migrated to the ocean at other seasons than in 

 the cold weather. As I have stated, however, all the evidence negatives this conjecture. 

 Dming the hot months I have rarely observed it in the Hughli, which it appears 

 almost wholly to desert at that period. Its presence, however, as already stated, 

 has been reported to me during all the year, but it is exceedingly rare from May 

 to the end of June, so that it is to a certain extent migratory. The fishermen say 

 that with the approach of the hot weather the dolphin ascends the river, returning 

 with the rains. In July, and up to the end of September, its existence is demon- 

 strated by its being frequently caught in the nets of the fishermen, but were it 

 not for its capture, its presence could not then be determined. Living, as I have 

 done, for three years overlooking the river, I have never observed a dolphin rise 

 during the rains, although I have watched most carefully for them, and all the fisher- 

 men I have conversed with on the subject have told me that they never see them 

 rise at that season. This fact may be accounted for on the supposition that the 

 strength of the current is so great when the Hughli is fuU that the dolphin is 

 prevented from rising to the surface in the marked manner it does during the 



