Eris militaris is common across much of Canada and the United States. Males are overall brown to iridescent bronze with white markings. Females and immature spiders often show bronze highlights. Naturalists who are just beginning to learn the salticids are likely to confuse Eris males with Pelegrina males. In general adult male Eris are larger and stockier with relatively larger and more forward projecting chelicerae than their Pelegrina counterparts. Pelegrina males tend to have more white scaling on the face. N.B. Spiders in the genus Eris presents identification difficulties in part because of historical taxonomic inaccuracies. One of the major confusions involved E. militaris and E. flava. While this was clarified by Maddison (1986), see E. flava), questions and uncertainties remain. An interesting study by Hill describes many of the typical behaviors and daily activities of E. militaris including locomotion, grooming, and predation.
Hill, 2002

Massachusetts – First State / County Records, References