Final answer:
The term for laying down a line in long flat bights is not explicitly provided in the references, but contour lines and hatching are related terms used in mapping and geology.
Step-by-step explanation:
The term used to refer to laying down a line in long flat bights, especially in the context of mapping and geology, is not specified in the provided references. However, in geology and cartography, terms like contour lines and hatching are commonly used to describe features on maps. A contour line is used to represent areas of equal elevation, and hatching or crosshatching may be used to indicate areas of different terrains or to symbolize areas of shade in map illustrations.