Particular Baptist is terminology that at least goes back to the English Baptists who were divided into Particular Baptists -- believed in a "particular" or limited atonement -- and General Baptists -- who believed in a general atonement. This theology would be represented by the First London Confession, Second London Confession, Philadelphia Baptist Confession, et al. In America the Particular Baptists gradually changed their modifier to Regular Baptist (and many dropped the Particular Atonement view as well). I am not aware of any group of Baptists (such as an Association, Fellowship or Convention) that calls themselves Particular Baptist, but some churches and individuals identify themselves that way to emphasize their view of the atonement (and probably avoid the terminology "Calvinist," which many Baptists don't like). I'm guessing on Historic Fundamental Baptist that he may be emphasizing the emphases of the original fundamental Baptists in the early 20th century on the "Fundamentals" before being fractured by all sorts of secondary issues. [But it would be better if he explains what he means.]