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POPULAR HISTORY OP LICHENS. 



possess, — the "Orchella weeds" of commerce, which are 

 divisible botanically into three classes : — 1. Such as have a 

 cylindrical tapering thallus; 2. those having a flattened or 

 compressed thallus; and 3. a mixture of the two preceding 

 forms. Of the first class the chief varieties are "Canary/' 

 "Barbary, or Mogador," "thick Lima/' and "Cape" Or- 

 chella weeds; while of the second the principal are the 

 "Angola/' "Madagascar/' and "thin Lima" weeds. Of 

 these the most valuable kind at present is the Angola weed, 

 from the Portuguese settlement of Angola, in South Africa ; 

 it is about an inch and a half to two inches in length. The 

 Canary variety, which includes the " Cape de Yerde weed" 

 from the Canary, Cape de Yerde, and adjacent islands off the 

 west coast of Northern Africa, has been the longest known 

 in commerce ; it is a delicate filiform species about half an 

 inch to an inch and a half long, and frequently of a dark 

 brownish colour. Next to these the Lima varieties, from 

 the west coast of South America, are greatly used by the 

 orchill-maker. The thick form is frequently six to eight 

 inches long, with thick tough segments, sometimes superior 

 in diameter to a goose- quill ; it usually occurs in the form 

 of fragments having a reddish cross section. The thin va- 

 riety has the characters described under R.fuciformis. The 



