I have the following Frates/Fratis relatives who lived and died in the Philadelphia area and in lower New Jersey. Has anyone ever come accross these folks?

Frederick Frates b. 1826 d. Dec 15, 1876
Anthony Frates 1863-1888
Mary Frates 1830-4/1/1894
Andrew Frates 1825-3/23/1868
Samuel Frates died 1920
A. Fratis 1788 -3/2/1863
Elize Frates died 20 years on 4/29/1876
Ida Frates died 17 years 10 mo on 8/5/1877
W.F. died 9 mo 9/3/1870
Jacob Frates died 11 mo 10/26/1866
Hannah Fratis died 2/28/1907

Most are buried in Mount Vernon Cemetery in Philadelphia. Some of the relatives became 7th Day Adventists. Any help appreciated. We now spell the name FRATIS.