From time to time I receive letters from members to whom I send specimens of mosses, asking for information regarding data on envelopes reading: Habitat, rocks, west hill, or Limestone crevice, west hill, Owen sound, Ontario. In the following sketch I will endeavor to tell something of this station: Great fissures have their beginning at the edge of the cliffs facing the city of Owen Sound, looking east, and run due west for a distance of from one-quarter to three-quarters of a mile. In depth they are from fifteen to thirty-five feet, and the average width is two-and-a-half feet. The perpendicular walls are smooth with the exception of occasional ledges projecting out not more than six inches. At the base of the cliffs facing the city where considerable quarrying is done, I found a fossil specimen in an excellent state of preservation and resembling in appearance a species of Anomodon. And now, if the reader will, in fancy, accompany me on this August afternoon, I will mention such plants as I find while exploring this station. Starting from the east end of the fissures where a slight deposit of soil has gathered, shrubby, half-starved aspens grope for a precarious living; silverywhite lichens and Grimmia apocarpa, in contrasting colors, are dotted on the flat surface of the rocks; crisped, curled cushions of Tortella tortuosa are scattered about while in the partial shade of the aspens, Hedwigia albicans wanders at will over the limestone boulders. As I wander westward, the vegetation is more frequent and the edge of the crevice is quite moist, so I find hanging over the walls Aulacomnium androgynum, Anomodon viticulosus, and great, fruited, loose cushions of Bartramia pomiformis. Just under these I find Didymodon rubellus and Myurella Careyana, always hopelessly mixed. Still farther west, where cedars shade the crevice, are Hylocomium Pyrenaicum, Tortula mucronifolia, Thuidium delicatulum, and, again, Tortella tortuosa, the last named one fruited in this place. From the edge of the crevice to the sheer walls on the north, a distance of a few hundred feet, Thuidium abietinum is found at home on the rocks in the open and under the shrubs.