This little book was very useful in trying to figure out which parish records to look for my ancestors in. They could stay in one place but their parish would change. Conversely, knowing what parish they had records in, I could look at the map and see what area they were in. The map, however, is very difficult to puzzle out. The type is very readable in the high-res color PDF, but figuring out which name applies to what boundary is the hard part. Anyway, check this book and then look in the Family History Library, Maryland State Archives, or Maryland Historical Society for microfilm of the parish records. NB: There are very few personal names in this book.