You are right!They are listed with the last name "NICHOLAS" and there are others...According to the transcription by the Elsie Historical Society...
Alfred L, d. 9 May 1878Parents were WE & SH Nicholas Andrew J. d. 6 May 1868 lived to be 28 yrs 10 mos 23 days James H. d. 8 Feb 1881 lived to be 37 Parents J & M Nicholas Jonathan d. 10 Mar 1882 lived to be 81 yrs 1 mo 3 days Minnie d. 10 Feb 1871 lived to be 4 days. Parents WE & SH
This is all the information available.It would be to your advantage to pick up a copie of this and other cemetery transcriptions from Clinton County through the Elsie Historical Society.
One reason is that if there are females who married, they would be burried under the married name, but often the transcriptions tell who their parents are.So in my research, I have also painstakingly read down the "Parents" column with some luck -- so it is worth the time.
I looked in the Riverside, Elsie Village, Ridge Rd., Eureka, for the name Nicholas with no luck, however there are 9 in the Maple Grove Cemetery transcription!
Hope this helps...
Jack Sheldon, Jr., CPA Mesa, Arizona (formerly of Owosso, MI)