J. H. Emerton (1847-1931) was one of the pioneers of North American arachnology. Although widely traveled, much of Emerton’s field work was done near his home in upland and coastal areas of Essex Co., MA. Emerton’s 1904 note in Psyche recounts his observations of Pellenes cristatus (Habronattus borealis). In June 1901 Emerton and George Peckham* were exploring the local salt marshes where they found many “red-faced” male Habronattus spiders and initially identified these as immature H. coecatus. Ultimately they determined the jumpers were sub-adult male H. borealis. The immature males of both species show red scaling on the clypeus (see videos). Adult male H. borealis, however, show no red scales while male H. coecatus retain the red clypeus when fully mature. More than a century after their field studies H. borealis continue to inhabit the same coastal marshes visited by Emerton and Peckham*.
George W. Peckham(1845-1914) and Elizabeth Peckham (1854-1940) established salticid studies in North America and coauthored their seminal work – Revision of the Attidae of North America, 1909.
Emerton 1904; Peckhams, 1909; Wikipedia – George and Elizabeth Peckham

Massachusetts – First State & County Records, References