24 
F. A. Shillingford —On the Kusi River. 
[No. 1, 
Karatoya and near Dinajpur, where Dr. Buchanan Hamilton 1 mentions 
the occurrence of Jchari , or the white clay of the ftajmahal inter-trap- 
pean beds in digging a well. In most places these beds are what 
are termed in geological works in India, the “older alluvium” 
but it is not clear by what process they came to cover the highest tracts 
of the country; but the influence of this barrier in checking the drain¬ 
age of the country in the earlier days of the building up of the Grangetic 
plain and even probably now must be apparent to all knowing the dis¬ 
tribution of the Ganges alluvium. 
These three openings in this high tract of the country corres- 
Three larger Estua- pond to the three larger estuaries in the 
ries correspond with seaboard at the head of the Bay, above 
3 gaps in the ridge. described, and knowing as we do that the 
flanking estuaries have been occupied separately by the two great 
rivers of Bengal, it seems but reasonable to suppose that there 
Kusi probably hold- mus t have been a time when the Kusi, 
ing an independent holding an independent course and absorbing 
course to the Sea. the southern drainage of the Himalayas up 
to the eastern confines of Sikhim, passed through the central opening 
and flowed into the sea through the Harinaghatta Estuary, as a third 
great river of Bengal. 
A map 50 9 miles to the inch, taken from Messrs. Keith Johnston’s 
Atlas, published in 1891, with dotted lines indicating the various align¬ 
ments of the Kusi—hypothetical as well as actual—is annexed. 
1 Description of the Dinapur District, Calcutta, 1833. 
