x PREFACE. 
by J. Perthes in 1893, has again been used. The geographical 
distribution of the species described in this section has been worked 
out by Mr. N. E. Brown, A.L.S. The manuscript has been prepared 
for the press and the proofs have been checked by Mr. C. H. Wright, 
A.L.S., Assistant in the Herbarium, Royal Botanic Gardens, Kew. 
jD a 
Kew, 
August 20, 1917. 
