One of the FamilySearch microfilms that has been digitized is the St. Mary’s (Niagara Falls) Church records (DGS 7586295). Included in the records is a section titled “Burial Register” in which there is a chronological listing of deceased members beginning in 1861 (image 498 of 537).
Link: https://www.familysearch.org/ark:/61903/3:1:3QS7-89FQ-WCD9?
The beginning records are in Latin and the microfilm is not very clear to read. Luckily, many of the entries were written in a dark pen and are pretty clear to read.

The register for the first ten years contains entries in a paragraph style, then in 1870 (starting at image 520 of 537) it switches over to a column type of entry. The entries include:
- Date of death
- Name of decedent
- Disease
- Age
- Last Sacraments
- Lot number

The lot number was eventually dropped from the columns. Not surprising as no information was being added to that column anyways.
The entries stopped at the end of June 1901 (image 534 of 537) and a notation states that entries beginning on 5 July 1901 were going to be in the new book.