LICHENS AND THE NATURALIST. 61 



lichen occurs on the Pacific coast. Graphis, Arthonia 

 and a few other genera are largely southern, etc. It 

 is also well to fix in mind their altitudinal distribution, 

 80 that no time will be wasted in looking for lichens 

 in the lowlands which occur only at considerable eleva- 

 tions. 



In a general way it may be advised to begin the 

 collection with the highest altitudes and to descend 

 gradually, carefully examining trees, rocks and soil. 

 Rocky ledges at high altitudes will be covered by large 

 foliose and fruticose lichens, as well as a host of crus- 

 tose forms. Some of the Parmelias may be several 

 feet in diameter. If the rock is not too rough the 

 lichen can be peeled off readily : begin on one side, 

 with the carpenter's chisel, or the table-knife, gradually 

 loosen it and roll the edge over, keep on, slowly and ^ 

 patiently, and you will succeed in removing it entire ; 

 if the plant is dry and brittle it will be necessary to 

 moisten it with water before trying to remove it. 

 After it is removed lay it flat between two sheets of 

 paper and place it in the portfolio, or leave it rolled 

 up and put it in the collecting-box. Umbilicarias, 

 Gyrophoras, Stereocaulon, Gladonia and some others, 

 will occasion no trouble in removing them from rock, 

 as they are only loosely attached. If they are dry 

 and brittle it is well to moisten them before handling 

 much. Some difficulty will be encountered in remov- 

 ing foliose lichens from the bark of trees ; usually only 

 fragments can be obtained. The fruticose lichens, no 

 matter where they occur, can be collected with but 

 little difficulty. Crustose bark-lichens require the 



