R. HEBER Howe, Jr.: NOMENCLATURE OF GENUS USNEA 379 
PLATE 13 
The Dillenian types of _Usnea barbata, etc. (reduced one half). 
PLATE I4 
LEFT-HAND FIGURE. The Linnean specimen of Lichen barbatus in the Linnean 
herbarium pease reduced). This specimen has little claim to be considered a type 
bec its macnn twenty-two years after the species was originally described. 
RIGHT-HAND FIGUR The Acharian material of Usnea barbata, var. articulata 
(L.) Ach., in the nes Society herbarium (reduced one half). 
