200 



WILLIAM S. COOPER 



Upon the bare rock surfaces grow crustose lichens, together with 

 numerous tufts of Grimmia ovata Web. & Mohr (fig. 1). This 

 species is found as near to the water as any of the lichens, and 

 frequently lower, and clings as closely to the rock. It is the most 



X 







Fig. 1 Bare rock shore of Rock Harbor. A belt of Grimmia uvula (black), 

 with foliose lichen zone above it. 



abundant moss at the lower edge of the crustose lichen zone, but 

 two other species are usually present. Orthotrichum anomalum 

 Hedw., which is commonest a little higher up, and Hedwigia albi- 



