F. A. Shillingford —On the Kusi River. 
23 
1895.] 
all these aspects of the case it would appear probable that the Ganges 
turned away eastwards during the first half of the 16th century, and the 
probability would amount almost to certainty if we were to admit that 
the western channel shown in De Barros’ Map is the original Bhagirathl, 
as it must have been recently vacated to appear so conspicuous. 
In conclusion, I would beg to remark that the whole subject is a 
vast and interesting one, and only the more prominent features have 
been here touched upon with a view, principally, of pointing out the 
probability of the Kusi and Ganges changing their courses, and the 
attendant dangers, and from the evidence adduced I think we are fairly 
entitled to conclude that both these catastrophes are certain to occur 
in the not distant future. 
Two points of special interest to Geologists crop up from these 
Formations similar investigations. The first is that we here see 
to Sussex Weald, in vast fresh-water beds of sand alternating with 
progress in the Delta. c lay, with here and there thick deposits of 
fresh-water Shells in the Caurs ( vulgo , Ghowrs ) or lagoons forming far 
inland by the action of rivers ; whilst in the newly forming portions 
of the Delta itself we may expect to find areas of strata containing 
marine organisms alternating with fresh-water, or estuarine beds, with¬ 
out the aid of general up-heaval or depression of the country. This 
throws somelight on the probable mode of formation of the fresh water 
and fluviomarine beds of the Weald of Sussex, a subject of such 
controversy amongst English geologists. 
The second point of interest is that beginning at the Maniharl Hill, 
High ridge of Coun- in the Purneah District on the left bank of 
the Gan Sf s > and g oin S eastward and south- 
Hills. ward, a high ridge of country can be traced, 
with gaps here and there, right away through Gaur, the Borine of 
Rajshahi and Bogra through the Madhupur Jungles, away to the Assam 
Hills, between which and the Rajmahal Hills it forms a sort of barrier 
between the Gangetic Plain and the Delta proper. The principal per¬ 
forations or gaps in this ridge are, (1) the channel of the old Brahma¬ 
putra above Diwanganj ; (2) The channel of 
the present Brahmaputra at Jafirganj, which 
probably carried the Kusi at one time, and 
(3) the channels of the Mahananda and Ganges which are practically 
the same between Rajmahal and the Borine, with the narrow Gaur ridge 
forming an island in this opening. This ridge is composed of limestone, 
kar/kar , and brightly-colored variegated clays in the case of Maniharl 
Hill, and farther east of yellow and reddish clays with katjkar beds un¬ 
covered by the newer alluvium. Similar beds occur on the banks of the 
Three gaps in the 
Ridge. 
