Are your ancestors from Starr County? If they are and you are currently doing research then this may be able to help you out. These are some resources when it comes to cemeteries in Starr County Texas.
Find A Grave -They Have 55 Recorded Cemeteries but many don’t have any listings yet.
US Gen Web Project - Lists Cemeteries compiled by David Moreno up until May of 2011 and also has a link to a pdf file that he has created listing almost if not all the cemeteries in Starr County Texas.
David Moreno and Google Maps – This is a link to Google Maps where David keeps up to date all the cemeteries that he finds in Starr County. I also believe that anyone can help with this project, since there are four collaborators listed. He made me aware of it when I informed him of the name to one of the cemeteries listed on his PDF file. There are more than the 55 cemeteries listed on Find A Grave.
Map of Project on Google Maps
Image is from Google Maps and it was accessed on 12-3-2011.