Misplaced marriage records for Aguascalientes?

I have been working on the index of Aguascalientes matrimonial investigations from the 1733/34 volume.

After the 1733 entries there are about 75 pages of records that are not matrimonial investigations (or at least not typical matrimonial investigations) as they do not follow the usual form, and are much shorter. These records extend from 1735 into the 1750s. They seem to be marriage records, but the terminology is different. The couple is typically indian, but occasionally mulato/mulata.

The official appears to be representative of the Bishop of Michoacan ("examor Synodal de este Obispo"), rather than the usual parish priest.

Some of the text is (this is from image 329; the whole group starts at about image 250):

"... aparecio Juan Manuel de la Cruz indio de el Pueblo de Jesus Maria de veinte anos de edad hijo legmo de Ygnacio de la Cruz difunto y de Maria de la Rosa y dixo: tener tradado matrimonio con Maria de la Cruz ..."

If I read the next section correctly, it says that they have then gone through the necessary proceedings and have been instructed in the mystery of faith.

There is reference to the provisions of the Council of Trent; as well as witness's names (but no statements).

What is missing are the usual terms such as "inter missarum solemnia," "in faciea Eclicia" and "case y vele" that would be in a marriage record.

Occasionally, there will be the marginal note after the names of "case y vele" or "se casaron y velaron," but no date.

What are these records? (1) are they very abbreviated matrimonial investigations? (2) Are these marriages that have been formalized after the fact, or (3) Are they marriages that were not performed in a nuptial Mass?

George Fulton
Pleasanton, CA