Hello Janice,
From about 1874-1877 there was an epidemic of smallpox (''pokken '' in Dutch, a disease),
in Goeree-Overflakkee in which Melissant is. Maybe that was the cause?
and 1870-1873 in many places in Netherlands.
Their burials won't be there online, graves from such older times are often not there anymore
The only possibility I can think of is that they are registred in the archiv if they have those.
(archiv of Goeree-Overflakke, mail:
streekarchief@goeree-overflakkee.nl )
regards,
Jettie