Papers include professional correspondence, 1869-1905, largely with other entomologists; memorial tributes; personal recollections of former student and colleague, Charles A. Peters, 1874-1973; newspaper clippings; printed versions of published writings; and letters from other entomologists to Fernald's wife, entomologist Maria E. (Smith) Fernald (who lived from 1839 to 1919), about her work.

Correspondence to Fernald is arranged in two groupings and then alphabetically according to the surname of correspondent.