Source:
http://1940census.archives.gov/search/?search.census_year=1940&search.city=&search.county=Nevada%20County&search.page=1&search.result_type=image&search.state=AR&search.street=#searchby=location&searchmode=browse&year=1940
Downloaded April 3, 2012

Menu on the web page shows:
Maps (2)
	Nevada County 4 Pages
		Each "page" is saved in one JPG file.
		Named "Map_Nevada_1.jpg" through "Map_Nevada_4.jpg"
		Note: On maps 1-3, north is on the LEFT side
		of the image, not the top as typically expected!
	Prescott 1 Page
		Saved as "Map_Prescott.jpg"

Descriptions (6)
	Each "page" is saved in one JPG file.
	Named "Description_1.jpg" through "Description_6.jpg"

Census Schedules (23)
	Multiple pages (each in a JPG file) for each ED
	Saved in folders named "ED 01" through "ED 23"
	with the city, township (Twp) or portion of Twp.
	Filenames in these folders were the names inside the
	original ZIP file downloaded.  Original folder names
	were AR.50.ED.zip, where ED is the number of the
	enumeration district.