less the present location of the Jamuna. At that time the Brahmaputra used to flow to the east round the foot of the Garo Hills. The earliest evidence of the Brahmaputra river consists of a group of large Brahmaputra-size river scars which extend into the Sylhet basin flanking the southern edge of the Shillong plateau . The main river apparently extended east beyond this locality and then swung south into the Bay of Bengal. By the time of Rennell's mapping, this course had been abandoned in favour of a shorter route down what is still called the old Brahmaputra river past Mymensingh.