Incomplete Post: Accessing the Type field on an history record

I have a datagrid, that shows a list of history records for an account.  I want to filter the grid programmatically to not include database change records.  However, I cannot figure out how to specify the history type value in my query criteria to database change.  I tried the numeric value of 262156, but got a build error that a Type was expected, not an integer.  Then I tried to use the HistoryType class, but cannot find any documentation on what value to use in my criteria.  How do I say critiria.add(type not equal to 'database change')?