198 Mammals of Eastern Asia 
Asia; two others, Inia and Stenodelphis, in South America. 
* 'White" Dolphins occur both in this family and in the family 
Delphinidse. 
The River Dolphins are distinguished from the True Dol- 
phins by having the vertebrae of the neck all distinct and sepa- 
rate, the skull squarish at the back, the jaws produced into a 
long narrow beak with many teeth in each side, and the line of 
junction or symphysis of the two halves of the lower jaws very 
long from front to back. 
Of the two Asiatic genera mentioned above, Platanista is 
included in this book only because it goes far up the Brahma- 
putra River into Assam and is present in the Karnaphuli River, 
at Chittagong. Both of these streams enter the region treated. 
The White-flag Dolphin, Lipotes vcxillifer, first made 
known to science in 1914, is a long-snouted white Dolphin found 
in Lake Tungting, 600 miles up the Yangtse River, China. 
It bears a remarkably close resemblance to Inia, one of the 
fresh- water Dolphins of South American rivers. Lipotes vexil- 
lifer is colored above pale blue-gray, appearing whitish at a 
distance, and is white below. The length is about 8 feet in males, 
7 feet in females ; the weight 300 pounds. On the back is a low 
triangular fin, its base about twice as long as its height. The nar- 
row part of the snout is about 14 inches long and only 4 inches 
broad. The flippers are about as long as the snout. The eyes are 
very small and the ear openings are like pin pricks. The blow- 
hole, longitudinal and somewhat rectangular, opens definitely on 
the left side of the head. It can be closed by a special valve. The 
small bony crests on the skull behind the rostrum are equivalent 
to the large "maxillary crests" of Platanista. Such crests are 
undeveloped in the South American Inia. The number of teeth 
on each side of the jaws is 32 to 33 above, 31 to 33 below. 
The food is reported to consist largely of eel-shaped catfish 
which the Dolphins grub out of the lake mud with their beak- 
like snouts. The Dolphins swim in schools of ten or fifteen indi- 
