Darwin Core term name: decimalLongitude. Definition in Darwin Core: The geographic longitude (in decimal degrees, using the spatial reference system given in geodeticDatum) of the geographic center of a Location. Positive values are east of the Greenwich Meridian, negative values are west of it. Legal values lie between -180 and 180, inclusive.

Nullable<double> DecimalLongitude { get; set; }

Property DecimalLongitude As Nullable(Of Double)
	Get
	Set

property Nullable<double> DecimalLongitude {
	Nullable<double> get ();
	void set (Nullable<double> value);
}

abstract DecimalLongitude : Nullable<float> with get, set