'Middlesex County, NJ' definitions:

Middlesex -- U.S. County in New Jersey

From: Gazetteer 2000
Name :
Middlesex -- U.S. County in New Jersey
Population (2000) :
750162
Housing Units (2000) :
273637
Land area (2000) :
309.719506 sq. miles (802.169805 sq. km)
Water area (2000) :
12.792287 sq. miles (33.131870 sq. km)
Total area (2000) :
322.511793 sq. miles (835.301675 sq. km)
Located within :
New Jersey (NJ), FIPS 34
Location :
40.494044 N, 74.383918 W