it has been determined that carpet-forming mosses are good indicators of heavy metal deposition, since they are dependent on their supply of nutrients from above rather than from the substrate. samples of the common carpet-forming pleurocarpous moss pleurozium schreberi (brid.) mitt, and the underlying soil were collected during the summer and early fall of 1975 from 105 sites in northwestern ontario. analyses were carried out on all samples for the heavy metals cd, cu, fe, hg, mn, ni, pb and zn, using atomic absorption spectrophotometry. results were expressed as ppm (dry weight). soil ph and loss on ignition were also measured. the results were in general agreement with those reported elsewhere in the literature. as expected, moss analysis was shown to be a more reliable indicator of metal deposition than soil analysis.