We don't have the images for the period 1778-1807, and without those it's hard to tell.
Marisaria* would indicate that the name was difficult to read and that is what it looked like. It could easily be Margarita.
Margarita Armetta from the baptism book 1764-1773......if the page # is 99 and you can't find the record there...then go to the next page (100) and check the left side of the page. Some recorders listed the page # of a new page on the right side of the page and the same # on the left side of the next page, as in this case.
The record you refer to is for "Francesca Maria Vincenza Margarita Armetta, which you'll find on the bottom of the left side of page 100. If the child had several names you may find each of the names listed separately in the index. Her parents are Vincenzo and Giacoma. Their marriage is on page 38 of 1755-1777 marriages.
Hope this helps
Angelina