ECOLOGY OF ISLE ROY ALE. 229 



39. Lecidea lactea (Flk.). In rather small patches on exposed slop- 

 ing and vertical rocky cliffs. Common on the water side of crustaceous 

 or lower lichen zone. A white lichen with black dots. I, 1; V, 2. 



40. Endoccurpon miniatum (C) Ach. Rock surfaces with little soil, 

 along Siskowit cabin trail, V, 4. Also in lower crustaceous lichen 

 zone. V, 2; I, 1. Not abundant. 



41. Endocarpon mimatum saauaticum. In lower crustaceous lichen 

 zone within reach of winter waves. Not abundant. I, 1; V, 2. 



42. Ichmodophila aeruginosa. On decaying bark of fallen trees along 

 ■Siskowit cabin trail. Scarce. V, 4. 



43. Rhizocarpon {Buellia) geograpMcum (C) DC. A small green 

 lichen occurring in small patches on rocky shores in crustaceous lichen 

 zone, often near the water. Can only be removed by chipping away 

 the rock on which it grows. Fairly common. I, 2; V, 1. 



Mosses. 



44. Sphagrmm teres Aug., var. tenellum RL, Mcolor. 



45. Sphagnum ro'hustum RL, var. gradle El., palleus. 



46. Sphagnum girgensohnii Russ., var. molle Crev., palleus. 



47. Sphagnum platyphyllum Sull., var. subsimplex Cdbg., glaucum. 

 The above sphagna were abundant in all the bog areas of the island, 



and were of occasional occurrence on the low ground along creeks and 

 elsewhere on low wet ground. I, 4; I, 6; II, 2; II, 5; III, 5; IV, 10; 

 V, 5; V, 8; V, 11. 



48. Georgia p&lluoida {Tetraphis pellucida). Woods along Siskowit 

 <;abin trail. V, 4. 



49. Polytrichmn commune C. A most vigorous moss growing in 

 dense colonies; in places along the forest-bog tension zone successfully 

 invading the sphagnum masses. The only plant of the woods that 

 could hold its own against the invasion of the Sphagnum into the forest. 

 ■Confined to moist or wet places. V, 4. 



50. Polytrichum strictum Banks. Rather bare exposed places along 

 Greenstone Ridge, also "natural openings" along the Siskowit cabin 

 trail. V, 2; Y, 4. 



51. Dicraniim schreberi. Near sphagnum bog at end of cabin trail. 

 V, 5. 



52. Dieranum fuscescens Turn. Occurs in small heads or clumps on 

 dead wood. In woods. V, 4. 



53. Dieranum longifolium Hedw. Woods along Siskowit cabin trail. 

 ■V, 4. 



54. Dieranum, scoparium (C) Hedw. Woods along Siskowit cabin 

 trail. V, 4. 



55. Dieranum undulatum Voit. Woods along Siskowit cabin trail. 

 V, 4. 



56. Grimmia unicolor Hook. Confined entirely to small crevices and 

 •cavities in the bed rock of the gently sloping shore. It occurs nearer 

 to the water's edge than any other form of vegetation observed on the 

 island. No other mosses approach it in nearness to the water's edge, 

 and it surpasses even the hardiest lichens of the crustaceous zone in 

 this respect. Very hardy, and at times highly xerophytic. I, 1; V, 2. 

 It is of a very dark greenish brown color. 



