When Beaver suggests they keep the dog he's found, Ward reminds Beaver that the boys had a dog already, but didn't take care of him, so they gave the dog away. That dog must have been the one they got earlier in the season at the end of Captain Jack (1957).
It's shown that Miss Canfield is left-handed.
June, speaking to Ward, states that Mrs. Rayburn was her teacher when she was in school.