Although this is an old post, it still comes up when one searches for John Clarke, so I wanted to add my usual correction of Calnek's error for anyone who comes across it. Richard Neiley correctly stated that Jane Clark, John's sister, married John Neily, but several others have followed Calnek in marrying her to Joseph Neily. By the time Calnek did his research, there seems to already have been confusion in the family about the immigrant ancestors and he has mixed up the Johns and Josephs. The father of the immigrant family was Joseph Neily, rather than John, and he arrived with his wife Mary, three sons (Robert, Joseph, Jr., and John), daughter Martha and son-in-law James Reagh, and probably daughter Rebecca (who may have been born here). These are clarified in Joseph, Sr.'s will 1777, and John's will (1821) makes it clear that he is the one that married Jane (Clark)and became the ancestor of all later Neilys and Neileys of NS lines. We do not know what happened to Joseph, Jr., nor Rebecca, and I have found no evidence to support Calnek's statement that Robert moved to Walton, Hants Co., and (in his original notes) had a family there.
I have also been unable to find any evidence that the John Clark who was Jane's brother and the Windsor settler with McNutt's colonists was the one who married Lydia Green in 1736 in County Roscommon. If anyone knows of the source for this, I would very much like to hear of it.