List - how to find item by reference?

List - how to find item by reference?

I want to make something like this:
class BaseClass
{
private List<MyClass> list;
private void addData()
{
list.Add(new MyClass(this));
}
public void removeData(MyClass data)
{
list.Remove(data);
}
}
class MyClass
{
private BaseClass baseClass;
public MyClass(BaseClass baseClass)
{
this.baseClass = baseClass;
// DO SOMETHING
calculationDone();
}
private void calculationDone()
{
baseClass.removeData(this);
}
}
My problem is that list.Remove() returns false and item is not removed
from the list. What's wrong with my code?