Question: what is the north south extension of west bengal

title: Geography of West Bengal
text: Mahananda River divides the district of Malda into two parts . The eastern part consists of undulating plains and some tilas and is made up of old alluvium and is a part of the Ganges delta . It is also known as Barind or Barendrabhumi . In contrast to the eastern part , the western part is made up of new alluvium and in this part River Kalindi joins the Mahananda River . The part of Malda lying to the north of river Kalindi is known as tal . This is a lowland and covered with swamps and beels ( small water bodies ) . Whereas the area south of the Kalindi is a very fertile land and is known as diara .