Hi Josephine,
I think I have a private email from you to answer as well. You emailed me when I was at the Portuguese Genealogical Conference and Research Trip in Salt Lake City. I'm home now and playing catch up in the online world as well as my own world! LOL
You'll eventually get used to this changing of surnames at a whim type thing.
Looks like your Jacintho Miguel de Medeiros and wife Antonia Hermina do Rego was probably Jacintho Miguel de Medeiros over there and may have been just Jacintho Miguel, but due to other Jacintho Miguels, tacked on Medeiros to differentiate himself. More research will be needed. You'll also likely find the Medeiros somewhere back in his tree. Jacintho is the old spelling for what is now spelled Jacinto. I'm inclined to say that
"Jachinto" was a typo or someone transposing letters.
Antonia Hermina (and it may be Ermina, too), was most likely her name. Women didn't have surnames in that time period, but she somehow knew to state her family name of Rego so you are lucky! Because she was female, you do see them matching the surname to her gender in that time period, hence, the Rega.
Cheri Mello
Listowner, Azores-Gen
Researching: São Miguel island: Vila Franca, Ponta Garca, Ribeira Quente, Ribeira das Tainhas, Achada