Norman Gayford
Lovecraft Studies, #18 Spring 1989 lists his middle initial as L (in ToC, but does not include an initial on title page), but An Epicure in the Terrible lists his middle initial as R (in ToC and on title page). An Epicure in the Terrible mentions the Lovecraft Studies, #18 Spring 1989 essay in its "Contributors" notes so they are the same person.