7128 €etacea. 



male, the symphisis of the lower jaw measures 17 inches ; in the aduU 

 female only 12 inches ; the rostrum being thus 5 inches longer in the 

 former. 



The susu ascends very high up the rivers, if not quite to the foot of 

 the mountains. Hardwicke's drawing was " made from a living speci- 

 men 1000 miles above Calcutta." Major Tytler assures me that he 

 has seen them about 40 miles up the Jumna, and also at Raj-ghat 

 Mundi in the Dehra Dhoon ; likewise in the Indus and Sutlej near 

 Ludiana ; but these were doubtless of the species proper to the Indus 

 and its tributaries. The Gangetic susu is common throughout the 

 valley of Asam, in the Brahmaputra and its tributaries. Whether 

 inhabiting the Irawadi and other Burmese waters I am unaware ; but 

 have been assured that no such animals exists there. From the 

 minuteness of its eyes this creature is obviously adapted for turbid 

 rather than for clear water ; and it has never been observed out at sea. 

 It is migratory, as it occurs towards the Gangetic outlets only in the cold 

 season, as remarked by Dr. Cantor ; but at what particular season it 

 is observed in the Upper Provinces I have been unable to ascertain. 



The skull of a susu from the Indus, presented by the late Sir Alex- 

 ander Burnes, is of a conspicuously distinct species which I designate 

 Platanista indi, of Blyth. Maxillary crests wanting in the speci- 

 men. Larger and much more robust than P. gangetica, with the same 

 number of teeth, which are more than twice as stout as in the oLher^ 

 being much ground down by attrition in the specimen. Length of 

 skull 20|^ inches ; greatest width at zygomata 9^ inches ; depth of the 

 two jaws, with teeth in situ, measured in the middle of their length 

 .85^ inches, in P. gangetica barely If inches. Length of symphysis of 

 lower jaw 11 inches. Depth of zygomatic arch 2| inches. 



A coloured figure of probably the identical individual that furnished 

 the skull above described occurs among the Burnes' drawings. The 

 rostrum is represented as short in proportion to the length of the 

 animal, and the neck to be more contracted than in the Gangetic 

 species, which may be an error of the draughtsman. Colour also 

 much paler ; the lower parts dull albescent, abruptly defined in a line 

 from the gape to the tail-flukes. The specimen is evidently a female ; 

 whence the male should have a longer rostrum. The dimensions 

 assigned are " 7 feet long by 1 foot 3 inches deep.' Rudimentary dor- 

 sal fin as in the Gangetic species. Further information respecting thp 

 susu of the Indus and its tributaries is very desirable.* 



* The existence of the susu of the Indus, as a pivticular species, is referred to in 

 Professor Reinhardi's admirable paper on the Gangetic species, a translation of which 



