There are some claims that William Throop or Throope who emigrated to Barnstable, Mass before 1657 and then moved to Bristol, in what is now Rhode Island, was once a person named Adrian Scrope or Scroop who was seen in Hartford, Connecticut in 1660. This Adrian Scrope was said to be the son of Adrian Scrope the Regicide who signed the death warrant of Charles I (although he didn't have a son named Adrian) or another close relative of the Regicide.
The book America Heraldica (E. de V. Vermont, pub 1887 New York page 48) says:
Among his [Lord Scrope of Bolton] descendants was Colonel Adrian Scroop, the regicide, who was executed at Charing Cross in 1660. His son, Adrian, insecure in his person and property, with the paternal past following him everywhere, fled to Hartford, Ct., in 1660, and assumed the name of William Throop, to escape pursuit from his father's enemies. He changed, at the same time, the Scrope arms [azure, a bend, or] for the arms we reproduce here. Later, the emigrant settled at Bristol, R. I
A reference is given as "The History of the Regicides" by Henry R. Stiles. Henry Reed Stiles wrote a fair few books and articles but I have not been able to find the original book or article, or any other reference to "The History of the Regicides". It is not listed in the Library of Congress catalogue.
Does this book/article really exist or is this a fabrication?