LARK (THE), a river of Suffolk and Cambridgeshire. It rises, in several head-streams, near Rushbrook, in the SW of Suffolk; runs chiefly north-westward, past Bury St. Edmunds and Mildenhall, to the boundary with Cambridgeshire; traces that boundary for 5 miles; and proceeds 3 miles in Cambridgeshire to a confluence with the Ouse in the neighbourhood of Littleport. Its total length is about 26 miles. It was made navigable to Bury-St. Edmunds in 1700.

(John Marius Wilson, Imperial Gazetteer of England and Wales (1870-72))