The records are found at LDS FamilySearch:https://familysearch.org/search
You can use the search engine and also the browsing section which is at the bottom of the first page. (Browse all published collections....choose Canada, then Nova Scotia.)
The marriage record for Allan "McAulay" is found using the search engine and you will see that his parents are Donald and Mary. Allan was born in 1831 at Washabuck and married Sarah McDougall on June 19, 1871, at Baddeck, N.S. Her parents are Angus and Sarah.
Here is another good site for Nova Scotia records:http://www.genealogysearch.org/canada/novascotia.html
You may want to start with the Nova Scotia Historical Vital Stats (first item on list); you'll have to accept the terms and conditions to see these records.