Eighteen bryophytes new to Massachusetts and fifty-five additional new county records are reported, including the second collection of Pseudocrossidium hornschuchianum from the New World. Significant range extensions are briefly discussed in an annotated list, and additional noteworthy records are presented in an appendix. The bryophyte flora of the state as documented in the literature now stands at 329 species of mosses and 144 species of liverworts.