Data submitted in fulfillment of a 2008 Nantucket Biodiversity Initiative grant. Paper Abstract: We counted and measured Sphodros rufipes (Latreille 1829) pursewebs in two survey plots on Tuckernuck Island, Massachusetts. Tuckernuck is 50 Km south of Cape Cod, Massachusetts, and is entirely owned by private landowners or conservation organizations; biological research activities are supported and encouraged by residents on a limited basis. Our objectives were to quantify web density and determine the main components of the S. rufipes diet. We counted 479 webs in the two plots and report web densities between 0.058 and 0.18 webs/m2; denser than previously reported populations. Contrary to most previously published literature on S. rufipes, we noted the predominance of the grass-like sedge, Carex pensylvanica, rather than trees, as a web support. However, we also offer the first report of S. rufipes using a conifer (Pinus rigida) as a web support. Coleopterans and isopods made up 79 percent of the prey parts collected from 56 pursewebs. We suggest that the Tuckernuck population offers an opportunity to collect important long-term demographic data. Datasets: sphodrosWebLocations.csv - data from two specific areas sphodrosSpiderMeasurements.csv - measurements of live spiders borrowed from their webs sphodrosRandomWebLocations.csv - data for webs found by happenstance sphodrosDiet.csv - diet data from body parts collected from Sphodros webs sphodrosDataDictionary.csv